Input and Articulation System for Catheters and Other Uses

ABSTRACT

User interface devices, systems, and methods can be used for selectively bending of, altering the bend characteristics of, and/or altering the lengths of catheter bodies, guidewires, steerable trocars, and other flexible structures inserted into a patient during use. Optionally, a housing is coupled to a proximal end of a catheter, and movement of the housing by a hand of a system user is sensed and used as a movement command for articulation of the catheter. Alternatively, a sensor can be coupled to an elongate flexible body flexing outside of the patient so as to alter bending of a catheter within the patient. Movements generated through a combination of manual manipulation and powered articulations are facilitated.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/369,606 filed Dec. 5, 2016 (Allowed); which claims thebenefit of U.S. Patent Appln Nos. 62/263,231 filed Dec. 4, 2015 and62/326,551 filed Apr. 22, 2016; the full disclosures which areincorporated herein by reference in their entirety for all purposes.

The subject matter of the present application is generally related tothat of U.S. patent application Ser. No. 15/081,026 filed Mar. 25, 2016;the full disclosure which is incorporated herein by reference in itsentirety for all purposes.

FIELD OF THE INVENTION

In general, the present invention provides improved medical devices,systems, and methods, including improved input structures, systems, andmethods for selectively bending of, altering the bend characteristicsof, and/or altering the lengths of catheter bodies, guidewires, and thelike. The invention is particularly well suited for catheter systemsthat involve both manual manipulation of the catheter and poweredarticulation of the catheter within a patient, and may facilitateprocedures that include alternating between the two. The invention maybe included in or be used with articulation structures, systems, andmethods for articulation, in exemplary embodiments with systems having afluid-driven balloon array that can help shape, steer or advance acatheter, guidewire, or other elongate flexible structure extendingalong a body lumen.

BACKGROUND OF THE INVENTION

Diagnosing and treating disease often involve accessing internal tissuesof the human body. Once the tissues have been accessed, medicaltechnology offers a wide range of diagnostic tools to evaluate tissuesand identify lesions or disease states. Similarly, a number oftherapeutic tools have been developed that can help surgeons interactwith, remodel, deliver drugs to, or remove tissues associated with adisease state so as to improve the health and quality of life of thepatient. Unfortunately, gaining access to and aligning tools with theappropriate internal tissues for evaluation or treatment can represent asignificant challenge to the physician, can cause serious pain to thepatient, and may (at least in the near term) be seriously detrimental tothe patient's health.

Open surgery is often the most straightforward approach for gainingaccess to internal tissues. Open surgery can provide such access byincising and displacing overlying tissues so as to allow the surgeon tomanually interact with the target internal tissue structures of thebody. This standard approach often makes use of simple, hand-held toolssuch as scalpels, clamps, sutures, and the like. Open surgery remains,for many conditions, a preferred approach. Although open surgicaltechniques have been highly successful, they can impose significanttrauma to collateral tissues, with much of that trauma being associatedwith gaining access to the tissues to be treated.

To help avoid the trauma associated with open surgery, a number ofminimally invasive surgical access and treatment technologies have beendeveloped. Many minimally invasive techniques involve accessing thevasculature, often through the skin of the thigh, neck, or arm. One ormore elongate flexible catheter structures can then be advanced alongthe network of blood vessel lumens extending throughout the body and itsorgans. While generally limiting trauma to the patient, catheter-basedendoluminal therapies are often reliant on a number of specializedcatheter manipulation techniques to safely and accurately gain access toa target region, to position a particular catheter-based tool inalignment with a particular target tissue, and/or to activate or use thetool. In fact, some endoluminal techniques that are relatively simple inconcept can be very challenging (or even impossible) in practice(depending on the anatomy of a particular patient and the skill of aparticular physician). More specifically, advancing a flexible guidewireand/or catheter through a tortuously branched network of body lumensmight be compared to pushing a rope. As the flexible elongate bodyadvances around first one curve and then another, and through a seriesof branch intersections, the catheter/tissue forces, resilient energystorage (by the tissue and the elongate body), and movement interactionsmay become more complex and unpredictable, and control over therotational and axial position of the distal end of a catheter can becomemore challenging and less precise. Hence, accurately aligning theseelongate flexible devices with the desired luminal pathway and targettissues can be a significant challenge.

A variety of mechanisms can be employed to steer or variably alterdeflection of a tip of a guidewire or catheter in one or more lateraldirections to facilitate endoluminal and other minimally invasivetechniques. Pull wires may be the most common catheter tip deflectionstructures and work well for many catheter systems by, for example,controllably decreasing separation between loops along one side of ahelical coil, braid, or cut hypotube near the end of a catheter or wire.It is often desirable to provide positive deflection in opposeddirections (generally by including opposed pull wires), and in manycases along two orthogonal lateral axes (so that three or four pullwires are included in some devices). Where additional steeringcapabilities are desired in a single device, still more pull wires maybe included. Complex and specialized catheter systems having dozens ofpull wires have been proposed and built, in some cases with each pullwire being articulated by a dedicated motor attached to the proximalend. Alternative articulation systems have also been proposed, includingelectrically actuated shape memory alloy structures, piezoelectricactuation, phase change actuation, and the like. As the capabilities ofsteerable systems increase, the range of therapies that can use thesetechnologies should continue to expand.

Unfortunately, as articulation systems for catheters get more complex,it can be more and more challenging to maintain accurate control overthese flexible bodies. For example, pull wires that pass through bentflexible catheters often slide around the bends over surfaces within thecatheter, with the sliding interaction extending around not only bendsintentionally commanded by the user, but also around bends that areimposed by the tissues surrounding the catheter. Hysteresis and frictionof a pull-wire system may vary significantly with that slidinginteraction and with different overall configurations of the bends, sothat the articulation system response may be difficult to predict andcontrol. Furthermore, more complex pull wire systems may add additionalchallenges. While opposed pull-wires can each be used to bend a catheterin opposite directions from a generally straight configuration, attemptsto use both together—while tissues along the segment are applyingunknown forces in unknown directions—may lead to widely inconsistentresults. Hence, there could be benefits to providing more accurate smalland precise motions, to improving the lag time, and/or to providingimproved transmission of motion over known catheter pull-wire systems soas to avoid compromising the coordination, as experienced by thesurgeon, between the input and output of catheters and other elongateflexible tools.

Along with catheter-based therapies, a number of additional minimallyinvasive surgical technologies have been developed to help treatinternal tissues while avoiding at least some of the trauma associatedwith open surgery. Among the most impressive of these technologies isrobotic surgery. Robotic surgeries often involve inserting one end of anelongate rigid shaft into a patient, and moving the other end with acomputer-controlled robotic linkage so that the shaft pivots about aminimally invasive aperture. Surgical tools can be mounted on the distalends of the shafts so that they move within the body, and the surgeoncan remotely position and manipulate these tools by moving input deviceswith reference to an image captured by a camera from within the sameworkspace, thereby allowing precisely scaled micro-surgery. Alternativerobotic systems have also been proposed for manipulation of the proximalend of flexible catheter bodies from outside the patient so as toposition distal treatment tools. These attempts to provide automatedcatheter control have met with challenges, which may be in-part becauseof the difficulties in providing accurate control at the distal end of aflexible elongate body using pull-wires extending along bending bodylumens. Still further alternative catheter control systems apply largemagnetic fields using coils outside the patient's body to directcatheters inside the heart of the patient, and more recent proposalsseek to combine magnetic and robotic catheter control techniques. Inaddition to the technical challenges of (and large capital equipmentinvestments involved in) known robotic manipulators and catheterarticulation systems, the user interface of these systems are oftenlarge, complex, expensive, and/or configured to be used by a physicianseated outside the sterile field. While the potential improvements tocontrol surgical accuracy make all of these efforts alluring, thecapital total equipment costs and overall burden to the healthcaresystem of these large, specialized systems is a concern.

In light of the above, it would be beneficial to provide improvedmedical devices, systems, and methods, including improved input devices,articulation systems, and methods for users to direct and controlarticulation of flexible medical structures such as catheters,guidewires, and the like. Improved techniques for controlling theflexibility of elongate structures (articulated or non-articulated)would also be beneficial. It would be particularly beneficial if thesenew technologies were suitable to provide or enhance therapeuticallyeffective control over movement of a distal end of a flexible guidewire,catheter, or other elongate body extending into a patient body. It wouldalso be beneficial if these new techniques would allow enhanced ease ofuse of automated elongate flexible medical devices, ideally so as tofacilitate safe and effective use of powered articulation systems toaccess target regions within a patient body, or to achieve a desiredalignment of a therapeutic or diagnostic tool with a target tissue. Itwould also be helpful if these techniques could help provide enhancedcontrol over movements of a guidewire or catheter using a combination ofmanual manipulation with powered articulations, with the manualmanipulation and powered articulations occurring sequentially,concurrently, or a combination of both.

BRIEF SUMMARY OF THE INVENTION

The present invention generally provides new medical devices, systems,and methods, with exemplary embodiments providing improved inputstructures, systems, and methods that can be used for selectivelybending of, altering the bend characteristics of, and/or altering thelengths of catheter bodies, guidewires, steerable trocars, and otherflexible structures inserted into a patient during use. A sensor can becoupled to an elongate flexible body that extends from adjacent aminimally invasive access site into a patient during use. The sensor cantransmit signals associated with flexing of the body outside of thepatient. An articulatable distal portion of the inserted structure hasbend characteristics that can be altered in response to the sensorsignals, and a processor may operatively couple the distal portion withthe sensor so that the manual flexing of the body outside of the patientcan be used to control articulation of the distal portion within thepatient in a powered articulation mode. The flexible structure mayextend proximally from the distal portion toward (and in someembodiments through) the body, and the system may have a manual moderelying on manual manipulation of the flexible structure proximally ofthe body. Many embodiments may sense axial movement of the flexiblestructure in or out of an introducer sheath (or other access site), andassociated signals can be used to locally alter bend characteristicsalong one or more desired axial segments of the flexible structurewithin the patient. Still further embodiments may use input signals tolocally alter pushability or trackability along an elongate flexiblestructure. Regardless, many of the embodiments described hereinfacilitate control over movements of a guidewire or catheter through acombination of manual manipulation and powered articulations, with themanual movements and powered articulations optionally occurringsequentially, concurrently, or a combination of both.

In a first aspect, the invention provides a catheter articulation systemfor use by a user having a hand. The catheter articulation systemcomprises an elongate catheter body having a proximal portion and adistal portion with an axis therebetween. The distal portion of thecatheter body is configured for insertion into a patient through anaperture. A plurality of actuators is operatively coupled with thedistal portion of the catheter body. A housing is coupleable (optionallywirelessly) with the proximal portion of the catheter body andconfigured to be supported with the hand of the user. A sensor systemcan be mounted to the housing, the sensor system comprising anaccelerometer and/or a gyroscope and configured to measure movement ofthe housing in a plurality of degrees of freedom so as to receive amovement command from the hand supporting the housing. A processor maycouple the sensor to the actuators so that the distal portion of thecatheter body moves in response to the movement command.

As general optional features, the housing may contain a battery and bewirelessly coupled with the proximal portion of the catheter body.Optionally, a two-dimensional input device is mounted to the housing,the processor configured to move the distal portion of the catheter bodyin two additional degrees of freedom in response to input received bythe two-dimensional input. In preferred embodiments, the sensor measuresmovement of the housing in three or more degrees of freedom, optionallyin three translational degrees of freedom and two or three orientationaldegrees of freedom.

In another aspect, the invention provides a catheter articulation systemfor use by a user having a hand so as to treat or diagnose a patient.The catheter articulation system comprises an elongate catheter bodyhaving a proximal portion and a distal portion with an axistherebetween. The distal portion of the catheter body can be configuredfor insertion into a patient through an aperture. A plurality ofactuators can be operatively coupled with the distal portion of thecatheter body, and an input can be configured to facilitatereorientation by the hand of the user toward alignment with the inserteddistal portion of the catheter body and/or with the patient. A sensorcan be coupled to the input to receive a movement command having acommand orientation. A processor can be configured for coupling thesensor to the actuators so that, during use, the distal portion of thecatheter body moves, in response to the movement command, with acatheter movement having a movement orientation corresponding to thecommand orientation based on the reoriented input.

Advantageously, not all input axes need to be moved by the user into aprecisely parallel relationship with the corresponding output axes forsafe and efficient use of the systems described herein. Systems whichfacilitate user input re-orientation about just a single axis during aprocedure (ideally after the patient is positioned on the surgical tableor other patient support surface, after an image of target lumen orother tissue has been captured and shown in a display, and/or after thearticulated catheter has been inserted into the patient and advanced toor near the target treatment site) may provide significant efficiencybenefits. For example, the input may have a base surface that will restsecurely on a flat support surface while receiving rotational inputs,and which can be manually reoriented about a vertical axis by picking upor otherwise rotating the base surface relative to the support.Typically, the processor will be configured to calculate actuatorssignals to transmit to a subset of the actuators to induce the cathetermovement based on the movement command orientation, with the processoridentifying the subset of actuators using a transformation. Inputdevices described herein may facilitate reorientation in a plurality oforientations, and configurations of the system which facilitate movementof the input toward or into effective alignment using the hand of theuser may include input systems having an input base configured to bepicked-up and/or held, rotated, twisted, or otherwise to be readilyreoriented about any one, two, or all three input orientation axes(input roll, input pitch, and input yaw) during a procedure. Note thatthe input/output alignment need not be maintained throughout aprocedure; once the user provides effective alignment between the inputand output, the system can measure and store the aligned inputorientation and the user can move the input to a desired (often a morecomfortable or ergonomic) orientation. The system may measure thedesired input orientation and determine the change from the stored inputorientation to the desired orientation, and may calculate a transform sothat the input and output movements remain coordinated.

Optionally, the distal portion may be articulatable in two degrees offreedom, three degrees of freedom, or more. The movement command maycomprise a two-dimensional or three-dimensional movement command (ormore) including a change in position or a change in orientation or both,and the processor may determine a plurality of drive signals based onthe user's alignment of the input with the catheter structure so as todrive a plurality of separate actuators such that the movementorientation is aligned with the command orientation.

Also optionally, the sensor can comprise an accelerometer, a gyroscope,an inertial measurement unit, an image capture device, and/or a flexiblebody shape sensor. The movement command may comprising a movement of ahousing containing the sensor. The sensor may comprise an at least 2Daccelerometer and/or an at least 2D gyroscope, and the movement commandmay comprise tilting of the body in at least two degrees of freedom.When appropriate, the sensor may comprise an at least 2D accelerometer,an image capture device, and/or a flexible shape body sensor, and themovement command may comprise translating the body in at least twodegrees of freedom. In some cases, the input can be configured to bemoved by the hand of the user in 6 degrees of freedom, and the sensorcan receive the movement command in 6 degrees of freedom.

Preferably, a clutch input is coupled to the processor, and theprocessor is configured to induce movement of the distal portion of thecatheter in response to movement of the input body when the clutch inputis actuated, and to inhibit commanded movement of the distal portion ofthe catheter in response to movement of the input when the clutch inputis not actuated. Regardless, the input may comprise an at leasttwo-dimensional input component mounted to an input body. The processorcan be configured to induce aligned movement of the distal portion ofthe catheter body about a first coupling location along the axis inresponse to movement of an input body about a second coupling locationso that the user perceives that the coupling locations correspond. Thedistal portion of the catheter may include an articulatable segment anda therapeutic or diagnostic tool distal of the articulatable segment,and the first coupling location can be disposed distal of thearticulatable segment. As yet another general feature, the input canhave an axis and a rotational alignment input coupled with theprocessor. The processor can be configured to alter a rotationalalignment of a first lateral orientation about the axis of the catheterso as to correspond with a second lateral orientation about the axis ofthe input in response to an alignment command received by the alignmentinput. Advantageously, the input body can be elongate along the axis ofthe input body with a proximal portion and a distal portiondifferentiated from the proximal portion (often so as to facilitatetactile identification of the input orientation in the hand) The distalportion of the catheter body may have an elongate image with a distalend visually identifiable when displayed on a remote imaging system soas to facilitate manual rotational alignment, by the user, of the inputbody with the image of the distal portion.

In another aspect, the invention provides a catheter system for use by auser having a hand. The catheter articulation system comprises anelongate catheter body having a proximal portion and a distal portionwith an axis therebetween. The distal portion of the catheter body maybe configured for insertion into a patient through an aperture. Ahousing can be coupleable with the proximal portion of the catheter bodyand configured to be manipulated by the hand of the user while theproximal portion of the catheter body is coupled to the housing so as tomove the distal portion within the patient. A drive system may becontained within the housing and catheter body, and a processor can becoupled with the drive system so that the distal portion of the catheterbody moves in response to the movement command. Optionally, the housingcan be configured to be held in the hand during driven movement of thedistal portion or to be lifted by the hand onto a flat surface to restthereon during driven movement of the distal portion.

In general, the drive system may be contained within the proximalhousing and the catheter. The housing may have a bottom surface that isconfigured to rest in a stable position and orientation on a flatsupport, so as to remain fixed during actuator-induced articulation ofthe distal portion within the patient. The bottom surface may besufficiently positionally stable on the support so as to inhibitinadvertent movement during actuated articulation, such as not moving orbeing toppled over by forces of about a quarter pound or less, a halfpound or less, or a pound or less. Nonetheless, the housing may beslidable on the support in response to an axial manipulating forces, forexample, of a half pound or more, a pound or more, or the like.

The catheter systems described herein will often be configured for usewith a remote imaging system having an image capture device and adisplay. The input may have an input reference frame and the distalportion may have a distal portion reference frame, and the display mayshow the distal portion in a display reference frame that is associatedwith a relationship between the image capture frame and the distalcatheter frame. The system can be configured to maintain coordinationbetween, for example: a first movement command in the input referenceframe and a first catheter articulation as shown in the displayreference frame, the first movement command being prior to the manualmovement; and a second movement command in the input reference frame anda second catheter articulation as shown in the display reference frame,the second movement command being after the manual movement.

Any of the inputs described herein may optionally include a twist inputthat is manually rotatable relative to the housing coupled to theproximal catheter about a twist input axis extending along the catheteraxis, with the twist input optionally comprising a rotatable wheelsurrounding the catheter so that manually manipulating the twist inputmimics rotation of a proximal catheter handle. The processor can beconfigured so that rotation of the twist input induces articulation ofthe distal portion that mimics rotation of the catheter body about theaxis without rotating the proximal portion of the catheter adjacent theaperture. For example, rotating the twist input clockwise may causelaterally deflection(s) of the distal catheter portion to propagateclockwise about the catheter axis by an amount roughly equal to (orotherwise proportional to) the input twist.

Any of the processors of the catheter systems described herein mayoptionally have a manual movement state and an actuated movement state.A sensor can be coupleable with the housing so as to transmit manualmovement signals indicative of manual manipulation of the housingsuitable for manually moving the distal portion of the catheter withinthe patient. Suitable sensors may include any of the motion sensorsdescribed herein, contact sensors, translation sensors for sensingsliding of the housing across a surface (similar to a computer mousemovement sensor), or the like. The processor can be configured to changefrom the actuated movement state to the manual movement state inresponse to the manual movement signals. Optionally, the processor maybe configured so that the change from the articulated movement state tothe manual movement state: inhibits at least some articulation of thedistal portion; reduces an anchoring engagement between the distalportion and adjacent tissue; and/or alters a stiffness of the distalportion. For example, twist input may result in actuated movementmimicking rotation of the catheter, but other changes in the actuatedshape or pose of the catheter distal portion may be inhibited. Anchoringengagement may be decreased during sensed manual movement sufficientlyto facilitate manual repositioning of the distal portion within thepatient, optionally using an anchor decrease command calculated by theprocessor so as to reduce tissue engagement forces below a threshold.Stiffness changes during manual movement may comprise decreasingstiffness of a distal segment (so as to inhibit tissue damage),increasing stiffness of a proximal segment (so as to increase manualrepositioning accuracy) or both. In some embodiments, a mode inputswitch, button, or the like may be actuated to change the processor modebetween the manual an automated movement modes. The processor mayoptionally return to the automated mode if no manual movement hasoccurred for a threshold time, such as 5 or 10 seconds.

In another aspect, the invention provides a catheter articulation systemfor use by a user having a hand. The catheter articulation systemcomprises an elongate catheter body having a proximal portion and adistal portion with an axis therebetween. The distal portion of thecatheter body is configured for insertion into a patient through anaperture. A plurality of actuators is operatively coupled with thedistal portion of the catheter body, and a body is releasably attachedto the proximal portion of the catheter body. The body is configured tobe moved by the hand of the user in three degrees of freedom. A sensoris coupleable to the body so as to receive a movement command comprisingthe movement of the body in the three degrees of freedom. A processorcouples the sensor to the actuators so that the distal portion of thecatheter body moves in response to the movement command.

In another aspect, the invention provides a catheter articulation systemfor use by a user having a hand. The catheter articulation systemcomprises an elongate catheter body having a proximal portion and adistal portion with an axis therebetween. The distal portion of thecatheter body is configured for insertion into a patient through anaperture. A plurality of actuators is operatively coupled with thedistal portion of the catheter body. A housing is releasably attached tothe proximal portion of the catheter body, and is configured forsupporting with the hand of the user. A sensor system is mounted to thehousing. The sensor system comprises an accelerometer and is configuredto measure movement of the housing in a plurality of degrees of freedomso as to receive a movement command from the hand supporting thehousing. A processor couples the sensor to the actuators so that thedistal portion of the catheter body moves in response to the movementcommand.

In another aspect, the invention provides a surgical actuation systemcomprising an introducer. The introducer may include a sheath bodyhaving proximal end and a distal end with a lumen extending therebetween(the distal end being advanceable into a patient body), an input baseadjacent the proximal end of the sheath body, an input movable relativeto the base so as to receive a movement command from a hand of a user,and a sensor coupling the input to the base so that, in use, the sensortransmits a command signal in response to the movement command. Alongwith the introducer sheath, an elongate flexible body is included, withthe body having a proximal end and a distal end with an axistherebetween. The distal end can be configured for axial insertiondistally through the lumen of the sheath body and into the patient body.A drive system will often be coupleable with the elongate body, thedrive system comprising a processor and a plurality of actuators. Theprocessor can be configured to effect actuation of the actuators inresponse to the command signal so that the distal end of the elongatebody is urged to move with a movement associated with the movementcommand.

In another aspect, the invention provides an input system for use in asurgical system.

The surgical system may include an elongate flexible body configured forinsertion distally into a patient body, and a drive system coupleablewith the elongate body. The drive system may include an actuator and aprocessor configured to effect actuation of the actuator in response toa command signal so that the distal end of the elongate body is urged tomove with a desired movement. The input system comprises an introducersheath body having proximal end and a distal end and an axistherebetween. A lumen for receiving the elongate flexible body extendsaxially and the distal end is advanceable into a patient body. An inputbase adjacent the proximal end of the sheath body is also provided, andan input is movable relative to the base so as to receive a movementcommand from a hand of a user. A sensor couples the input to the base sothat, in use, the sensor transmits a command signal suitable forinducing the desired movement of the elongate body in response to themovement command.

In yet another aspect, the invention provides a surgical system for usewith tissue of a patient, the tissue accessible through a minimallyinvasive access site. The system comprises an elongate flexible proximalbody having a proximal end and a distal end, the proximal body extendingproximally from the minimally invasive access site during use. A sensoris operatively coupled with the proximal body, the sensor configured totransmit signals associated with flexing of the proximal body outside ofthe patient. An articulatable distal portion is configured to beadvanced through the access site toward the tissue, the distal portionhaving bend characteristics that can be altered in response to drivesignals. A processor operatively couples the distal portion with thesensor so that the manual flexing of the proximal body outside of thepatient can be used to control articulation of the distal portion withinthe patient during use of the system in a powered articulation mode.

In yet another system aspect, the invention provides a surgical systemfor use within a body lumen of a patient, the lumen accessible throughan access site. The system comprises an elongate body having a proximalend and a distal end with an axis therebetween, the elongate bodyincluding a first axial segment axially coupled with a second axialsegment. Each axial segment has an associated local lateral stiffness. Alength of the elongate body is configured to extend, during use, betweenthe access site and the distal end, and that length has a pushabilityand a trackability. A first actuator can be coupled with the first axialsegment and can be configured to selectively alter the local lateralstiffness (optionally by reducing the first local lateral stiffness, andoften without inducing bending of the first axial segment absentenvironmental forces) along the first segment in response to a firstsignal. Hence, the first signal can be used to tailor the pushabilityand/or trackability of the length of the elongate body for a particularbody lumen. In many embodiments, the first actuator is included in aplurality of actuators coupled with the elongate body, the pluralityincluding a second actuator coupled with the second axial segment. Thesecond actuator can be configured to selectively alter the localflexibility along the second segment in response to a second signal sothat the signals can be used to tailor, for the body lumen, thepushability of the length of the elongate body or the trackability ofthe length of the elongate body or both, with the exemplary actuatorscomprising balloons.

In yet another system aspect, the invention provides a surgical systemfor use within a body lumen of a patient. The lumen is accessiblethrough an access site, and the system comprises an elongate body havinga proximal end and a distal end with an axis therebetween. The elongatebody includes a first axial segment axially coupled with a second axialsegment and with a third axial segment, each axial segment defining alocal axial curvature during use. A first actuator is coupled with thefirst axial segment and configured to selectively alter the local axialcurvature along the first segment in response to a first signal so as tosteer the elongate body distal of the first actuator or align theelongate body distal of the first actuator with a target tissue. Asecond actuator is coupled with the second axial segment and a thirdactuator is coupled with the third axial segment. The second actuator isconfigured to selectively alter the local axial curvature along thesecond segment in response to a second signal; the third actuator isconfigured to selectively alter the local axial curvature along thethird segment in response to a third signal. The signals can be used totailor, for the body lumen, a safe anchoring engagement between the bodylumen and the elongate body such that movement of the elongate bodyrelative to the engaged body lumen is inhibited.

In a method aspect, the invention provides a surgical method comprisingreceiving a movement command defined by manually moving an inputrelative to a base. The input and the base can be included in anintroducer/input assembly, which can further include a sheath bodyhaving proximal end and a distal end with a lumen extendingtherebetween. The movement command can be received after the distal endof the introducer has been introduced into a patient body, and a sensormay couple the input to the base so as to transmit a command signal inresponse to the movement command. A processor may process the commandsignals and transmit drive signals to a plurality of actuators. Theactuators can be configured to articulate an elongate flexible bodyhaving a proximal end and a distal end with an axis therebetween. Thedistal end may be inserted distally through the lumen of the sheath bodyand into the patient body, and the drive signals may be transmitted sothat the distal end of the elongate body is urged to move with amovement associated with the movement command.

In the devices, systems, and methods provided herein, an input base cangenerally be affixed to the sheath body of an introducer/input assemblyduring use, and that can be configured to be supported by another handof the user. This facilitates defining a series of movement commands byrelative movements between the hands of the user, with the hand on theinput base stabilizing the introducer sheath so as to inhibit undesiredmovement adjacent the access site. This also allows the user to employhand motions that are similar to those used during manual cathetermanipulations, but to instead provide input commands that effect poweredarticulations of the distal portion of an inserted structure, and mayfacilitate transitions between manual movement of the distal portion andpowered articulation.

Optionally, the input can be a relatively simple (and optionallydisposable) structure. For example, the input may comprise an input bodyand an elongate flexible input shaft having a lumen. The lumen of theinput shaft may receive the elongate flexible body therethrough, and theinput shaft may extend distally of at least a proximal end of the inputbody. The input body may include a hemostatic valve and may optionallybe releasably affixable to a catheter or other elongate body extendingtherethrough, so as to inhibit inadvertent movement of the catheterproximal of the distal articulated portion. The input body may also bereleasably affixable to the input base, for example, when it is desiredto manually manipulate the catheter without inducing articulation. Thesensor can be coupled with the input body such that at least a portionof the command signal correspond to lateral flexing of the input body,which may allow the user to employ manual input commands that areparticularly easily associated with lateral bending of the distalportion of the elongate body within the patient, sometimes referred toas X-Y bending or deflection. The input shaft can extend distally of theinput body and can be slidably received in the lumen of the introducer.The sensor can be coupled to the input shaft such that at least aportion of the command signal corresponds to a change in axial overlapbetween the input shaft and the introducer assembly, allowing the userto employ manual input commands that are particularly easily associatedwith powered axial movement (including elongation and retraction) of thedistal portion of the elongate body (sometimes referred to as Zactuation). Note that the articulation system will often employ only asubset of these capabilities, with some systems allowing articulationonly in a single lateral direction.

The sensors of the devices and systems provided herein may take any of avariety of forms, with exemplary embodiments of the sensor comprising anoptical Fiber Bragg Grating (FBG), a flex-sensitive electrical component(such as one or more thin-film resistor deposited on the input shaft sothat it varies in resistance with flexing of the shaft), or the like.The sensor will often be mounted to the input, but may alternatively (oradditionally) be mounted to the elongate flexible body, particularlywhen the elongate body includes an FBG or other flex sensor system forproviding feedback to the processor to be used in generating the drivesignals.

The introducer (often the input base of the introducer) may optionallyinclude an introducer valve having a first configuration (such as withthe elongate flexible body axially affixed to the introducer sheath) anda second configuration (such as with the elongate flexible body axiallyslidable through the introducer sheath). The input may comprise an inputvalve having a first configuration (such as with the elongate flexiblebody axially affixed to the input) and a second configuration (with theelongate flexible body axially slidable through the input), and aninterface between the introducer and the input may have a firstconfiguration (with the input base axially affixed to the input) and asecond configuration (with the input axially movable relative to theinput base). The processor can be coupled to the valve of the inputbase, the valve of the input, and/or the interface so that the drivesignals are determined in response to the configurations. For example,when the input base is affixed to a catheter and the interface ismoveable relative to the input base, the drive signals may effect X-Ydeflection and elongation. When the catheter is affixed to the input andthe input and catheter are movable relative to the input base, the drivesignals may induce X-Y deflation but not elongation. When the input isaffixed to the input base and the catheter moves through both, the drivesignals may not induce any articulation (but may optionally facilitatelateral bending for tracking a lumen, guidewire, or the like).

The input preferably comprises a normally unactuated clutch input. Inuse, actuation of the clutch can define an initial state of the input.The processor can be configured to effect movement of the distal end ofthe elongate flexible body in response to a change of the input from theinitial state when the clutch remains actuated. The processor mayfurther be configured to disregard a change in state of the input whenthe clutch is unactuated. Hence, repeated actuated manual articulationof the input and unactuated manual returning of the input toward theinitial state can be used to effect cumulatively increasing articulationof the elongate flexible body.

A first connector typically couples the processor to the input, and asecond connector couples the proximal end of the elongate flexible bodywith the processor. The connectors may include quick-disconnect couplersand flexible cables. The processor can be disposed in a housing, and thehousing may also contain a battery and a pressurized fluid canister(both of which may be either rechargeable or replaceable). The actuatorsmay comprise fluid-driven actuators and the housing may have a size,weight, and shape suitable for manually repositioning with a single handduring use.

In many embodiments, the input comprises an X-Y lateral displacementinput, and an

X-Y laterally displacement of the movement command may induce lateralflexing the elongate flexible body proximally of the patient body duringuse. The drive system can have software and hardware configured toarticulate the distal end of the elongate flexible body in response tothe movement command with two degrees of freedom (including X-Y lateralbending) within the patient. The input may optionally comprise an axialZ displacement input, wherein the movement command comprises an axial Zmovement of the input along the axis of the elongate flexible bodyduring use. The drive system can be configured to, during use, do one ormore of the following two options: 1) axially move the distal end of theelongate flexible body within the patient body and relative to aproximal portion of the elongate flexible body in correlation with theaxial movement of the input, the axial movement of the input comprisingsliding movement of the input over the proximal portion of the elongateflexible body; and/or 2) laterally flex the distal end of the elongateflexible body in coordination with axial movement of at least a portionof the elongate flexible body so that the elongate flexible body movesalong a desired curve within the patient body. When the movement commandcomprises axial advancement of the input with the elongate flexible bodyadjacent the input moving axially with the input, the processor can beconfigured to drive the actuators so that the distal end of the elongateflexible body follows the desired curved within the patient body; and/orso that a curve along the elongate flexible body proximal of the distalend propagates proximally with advancement of the elongate flexible bodyin correlation with the axial movement. In some embodiments, theprocessor has an axial actuation recovery mode to effect coordinatedproximal movement of the distal end of the elongate flexible bodyrelative to the proximal portion of the elongate flexible body duringmanual advancement of the proximal portion of the elongate flexiblebody. Optionally, at least one of the actuators comprises a balloon.

The articulated bodies to be controlled by the user interface devices,systems, and methods described herein may have large numbers of degreesof freedom. In many embodiments (and particularly medical embodiments)it would be preferable for the system user to be able to providemovement commands with a single hand, often while supporting the inputdevice in that hand. In medical applications, the system user and inputdevice may be in or adjacent to a sterile surgical field, and may havetasks to perform with their other hand (optionally including insertingthe catheter body through an introducer sheath and into the patient. Oneoptional feature of many of the devices and system described herein isthat a body being manually moved by a hand of a user may optionallycomprise a housing, at least a portion of the processor being disposedin the housing. The movement command input into the system may comprisea change in position of the housing or a change in orientation of thehousing or both. Another optional feature is that the sensor that sensesthe movement command comprises an accelerometer, a gyroscope, aninertial measurement unit, an image capture device, and/or a fiber Bragggrating. Another optional feature is that the sensor comprises a 2Daccelerometer and/or a 2D gyroscope, for example, with the movementcommand comprising tilting of the body in two degrees of freedom. Yetanother optional feature is that the sensor comprises a 2Daccelerometer, an image capture device, and/or a fiber Bragg grating,with (for example) the movement command comprising translating the bodyin two degrees of freedom.

A number of optional feature may be included in embodiments whichreceive input commands as movements of a housing body or the like. Forexample, the sensor system that receives the movement command input as amovement of the housing may be configured to sense movement in thehousing in 2, 3, 4, 5, or 6 degrees of freedom, with the sensortypically transmitting signals to the system processor associated withmovement of the housing in each of the sensed degrees of freedom. Aclutch input may be coupled to the processor, and the processor may beconfigured to inducement movement of the distal portion of the catheterin response to movement of the body when the clutch input is actuated,and to inhibit commanded movement of the distal portion of the catheterdespite any movement of the body when the clutch input is not actuated.A two-dimensional input may be mounted to the body and coupled to theprocessor, with the two dimensional input configured to receive movementcommands that are in addition to those associated with movement of thebody. The processor may induce other movements of the distal portion ofthe catheter in response to these 2-D movement commands, the othermovements similarly being in addition to those induced by the movementof the body. The processor can be configured to inducement movement ofthe distal portion of the catheter body about a first coupling locationalong the axis in response to movement of the body about a secondcoupling location of the housing, with the induced movements beingaligned so that the user perceives the coupling locations correspond.The distal portion of the catheter optionally includes an articulatablesegment and a therapeutic or diagnostic tool distal of the articulatablesegment, and the first coupling location may be disposed distal of thearticulatable segment. Preferably, the body has an axis (it optionallybeing an elongate body or the like) and a rotational alignment inputwill be coupled with the processor. The processor can be configured toalter a rotational alignment of a first lateral orientation about theaxis of the catheter to a second lateral orientation of the body inresponse to an alignment command received by the alignment input, thealignment input ideally comprising a rocker switch biased to anintermediate position (so that the user can intuitively alter alignmentin opposed orientations), a thumb wheel, or the like. Electrical and/oroptical contacts may be included in a connector of the catheter and areceiver of the housing so as to facilitate transmission of feedbacksignals from the catheter to the system processor, with the feedbacksignals being indicative of a shape and/or location of the distalportion of the catheter and being available to the processor to moreaccurately drive articulation.

In another aspect, the invention provides a catheter articulation systemfor use by a user having a hand. The catheter articulation systemcomprises an elongate catheter body having a proximal portion and adistal portion with an axis therebetween. The distal portion of thecatheter body is configured for insertion into a patient through anaperture. A plurality of actuators is operatively coupled with thedistal portion of the catheter body. A housing is coupleable with theproximal portion of the catheter body and configured to be supportedwith the hand of the user. A sensor system can be mounted to thehousing, the sensor system comprising an accelerometer and configured tomeasure movement of the housing in a plurality of degrees of freedom soas to receive a movement command from the hand supporting the housing. Aprocessor may couple the sensor to the actuators so that the distalportion of the catheter body moves in response to the movement command.

In some embodiments, the housing contains a battery and is wirelesslycoupled with the proximal portion of the catheter body. Optionally, atwo-dimensional input device is mounted to the housing, the processorconfigured to move the distal portion of the catheter body in twoadditional degrees of freedom in response to input received by thetwo-dimensional input.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified perspective view of a medical procedure in whicha physician can input commands into an catheter system so that acatheter is articulated using systems and devices described herein.

FIG. 1-1 schematically illustrates a catheter articulation system havinga hand-held proximal housing and a catheter with a distal articulatableportion in a relaxed state.

FIGS. 1A-1C schematically illustrate a plurality of alternativearticulation states of the distal portion of the catheter in the systemof FIG. 1.

FIG. 2 schematically illustrates an alternative distal structure havinga plurality of articulatable sub-regions or segments so as to provide adesired total number of degrees of freedom and range of movement.

FIG. 3 is a simplified exploded perspective view showing a balloon arraythat can be formed in a substantially planar configuration and rolledinto a cylindrical configuration, and which can be mounted coaxially toa helical coil or other skeleton framework for use in the catheter ofthe system of FIGS. 1 and 2.

FIGS. 4A and 4B are a simplified cross-section and a simplifiedtransverse cross-section, respectively, of an articulatable catheter foruse in the system of FIG. 1, shown here with the balloons of the arrayin an uninflated, small axial profile configuration and between loops ofthe coil.

FIG. 4C is a simplified transverse cross-section of the articulatablecatheter of FIGS. 4A and 4B, with a plurality of axially alignedballoons along one side of the articulatable region of the catheterinflated so that the catheter is in a laterally deflected state.

FIG. 4D is a simplified transverse cross-section of the articulatablecatheter of FIG. 4, with a plurality of laterally opposed balloonsinflated so that the catheter is in an axially elongated state.

FIG. 5 schematically illustrates components for use in the cathetersystem of FIG. 1, including the balloon array, inflation fluid source,fluid control system, and processor.

FIG. 6 is a simplified schematic of an alternative balloon array andfluid control system, in which a plurality of valves coupled with theproximal end of the catheter can be used to direct fluid to any of aplurality of channels of the array and thereby selectably determine asubset of balloons to be expanded.

FIG. 7 is a simplified transverse cross-section of catheter wherein oneor more balloons can be inflated to radially engage a plurality of loopsof a helical coil so as to inhibit bending of a catheter axis.

FIG. 8 schematically illustrates a catheter articulation system in whichan input of the system is incorporated with an introducer sheath.

FIGS. 9-12 are perspective drawings showing an exemplary flat-patternsubstrate and associated balloon array generated by unwinding a helicalballoon pattern, along with an exemplary bonded balloon fabricationtechnique.

FIGS. 12A and 12B schematically illustrate balloon arrays in which theballoons are disposed over helical coil cores, and also show the effectsof varying balloon inflation density on a radius of curvature of acatheter.

FIG. 13 schematically illustrates bending of a diagnosis or treatmentdelivery catheter into alignment with a target tissue by actuating aplurality of articulation sub-portions or segments of the catheter.

FIGS. 14 and 15 are a perspective view showing an exemplary introducersheath/input assembly having a flexible joystick for receiving movementcommands using relative movement between hands or fingers of a user, anda schematic cross-section of the sheath/input assembly, respectively.

FIGS. 16 and 16A schematically illustrate use of the sheath/inputassembly of FIG. 14 in a manual mode.

FIGS. 16B-16E schematically illustrate use of the sheath/input assemblyof FIG. 14 in a 3-D input mode, in which flexing of the flexiblejoystick induces X-Y lateral deflection of the distal articulableportion of the catheter, and in which axial sliding of the joystickrelative to the introducer sheath induces axial elongation of thearticulable portion.

FIGS. 16F-16H schematically illustrate use of the sheath/input assemblyof FIG. 14 in a “follow-the-curve” mode, in which axial displacement ofthe catheter is measured and induces corresponding lateral deflectionsalong one or more axial segments of the articulable portion of thecatheter.

FIGS. 16I and 16J schematically illustrate use of the sheath/inputassembly of FIG. 14 in a local stiffness varying mode, in which axialdisplacement of the catheter is measured and induces localized changesin stiffness of the catheter so that a pushability and/or trackabilityof the overall catheter is tailored for that body lumen's geometry.

FIG. 17 schematically illustrates lateral deflection of an articulatedcatheter to provide gentle and releasable anchoring of the catheterwithin the body lumen, use of an anchored catheter as a base for 3-Dsteering of a catheter, and sensing of a curved path distal of and endof a catheter body by detecting deflection of soft distal guide tipagainst a lumen wall and/or guidewire.

FIG. 18 is a simplified schematic of a modular manifold having a stackof valve plate assemblies through which a multi-lumen connector extendsso as to provide controlled fluid flow to and from balloons of an array.

FIGS. 19 and 20 are a schematic illustration of an exemplary axialexpansion/contraction skeleton with axial expansion and axialcontraction balloons; and a corresponding cross-section of a skeletonhaving an axial series of annular members or rings articulated by theaxial expansion and axial contraction balloons, respectively.

FIGS. 21-23 are illustrations of elongate flexible articulatedstructures having annular skeletons with three opposed sets of balloons,and show how varying inflation of the balloons can be used to axiallycontract some portions of the frame and axially extend other portions tobend or elongate the frame and to control a pose or shape of the framein three dimensions.

FIGS. 23A-23H are illustrations of alternative elongate articulatedflexible structures having annular skeletons and two sets of opposedballoons, and show how a plurality of independently controllable axialsegments can be combined to allow control of the overall elongatestructure with 6 or more degrees of freedom.

FIGS. 24A-24G illustrate components of another alternative elongatearticulated flexible structure having axial expansion balloons andopposed axial contraction balloons, the structures here having helicalskeleton members and helical balloon assemblies.

FIGS. 25A-25F illustrate exemplary elongate articulated flexiblestructures having helical skeleton members and three helical balloonassemblies supported in opposition along the skeleton, and also show howselective inflation of subsets of the balloons can locally axiallyelongate and/or contract the skeleton to bend the structure laterallyand/or alter the overall length of the structure.

FIGS. 26A and 26B illustrate alternative articulated structures similarto those of FIG. 25, here with two balloon assemblies supported inopposition along the frames.

FIG. 27 schematically illustrates control system logic for using thefluid drive systems described herein to articulate catheters and otherelongate flexible structures per input provided by a system user.

FIG. 28 schematically illustrates a data acquisition and processingsystem for use within the systems and methods described herein.

FIGS. 29A-30 illustrate an alternative interface for coupling a modularfluid manifold to a plurality of multi-lumen shafts so as to providecontrol over articulation of a catheter along a plurality of segments,each having a plurality of degrees of freedom, along with portions ofsome of the plate modules of the manifold, with the plate modules herehaving a receptacle member that helps couple the layers of the plates toposts of the interface.

FIGS. 30A and 30B illustrate alternative housings containing fluidmanifolds, along with an exemplary input mountable to a manifoldhousing.

FIGS. 31A-31D illustrate an alternative articulatable structure having asingle multi-lumen core with balloons extending eccentrically from thecore, along with details of the structure's components and assembly.

FIGS. 32A and 32B illustrate a hand-held housing having a joystick andhow a movement command can be input by the hand holding the housing bymanipulating the joystick with a thumb of hand, and also schematicallyillustrate rotational alignment of the movement command with the distalportion of an articulated catheter about the axis of the catheter.

FIGS. 33A, 33B, and 33C schematically illustrate nine articulateddegrees of freedom of a catheter having three independentlyarticulatable segments, three orientational degrees of freedom of ahousing of an input device, and three translational degrees of freedomof the input housing, respectively.

FIG. 34 schematically illustrates sensing of a movement of the inputhousing using an FBG sensor, an accelerometer, a gyroscope, and/or acamera.

FIGS. 35A-35D schematically illustrate optional correlations betweendegrees of freedom of the input housing and articulated degrees offreedom of the catheter.

FIG. 35E schematically illustrates an alternative hand-held cathetersystem having a user interface housing which can be detached from themanifold assembly, with the user interface housing being movable by ahand of a system user so as to define movement commands.

FIGS. 36 and 36A-36D schematically illustrate another alternative inputsystem having a laterally flexible joystick that can be advanced axiallyto provide 3D input, and that is axially coupled to the catheter so thataxial retraction of the joystick advances the proximal portion of thecatheter.

DETAILED DESCRIPTION OF THE INVENTION

The present invention generally provides improved devices, systems, andmethods for controlling movement, and in exemplary embodiments, forinputting movement commands from a user to induce movement of elongateflexible articulated devices. The technologies described herein areparticularly well-suited for use by physicians and other health-careprofessionals, and will often be used to help direct computer-controlledmovements of catheters and other articulated devices when they areinserted into a body lumen or cavity of a patient. The elongate flexiblestructures may have 3, 4, 5, 6, 7, 8, or more active orcomputer-controlled degrees of freedom, and many, most, or all of thosedegrees of freedom may be distributed along an axis of the body lumenduring use; although many, most, or all of those degrees of freedom mayalso be within an open workspace (unsupported by surrounding tissues)during at least a portion of a procedure. The invention can help provideintuitive control over these and other articulated devices withsurprisingly simple input structures, with the input structuresoptionally being configured to be hand-held, optionally by a single handwhile the input structure is receiving input, for example, with themovements comprising movements of the overall hand and held inputstructure, or being provided from one or more digits of that hand,leaving the other hand free for other tasks. Alternatively, the inputstructure may be configured to be used while held in one hand of a userwith the input commands are provided by the other hand of the user, orthe input structure may be supported by a flat, roughly horizontalsurface so that the user can slidably reposition and reorient the inputstructure relative to the patient anatomy, imaging displays, or thelike.

Surprisingly, the user may manipulate fewer discrete and/or sensed inputjoint degrees of freedom than those being commanded. For example,movement of a hand-held housing of the input structure by the handholding the housing may be sensed in 1, 2, or 3 three positional degreesof freedom (such as displacement along X, Y, and/or Z axes) and in 1, 2,or 3 orientational degrees of freedom (such as rotation about roll,pitch, and/or yaw axes). Sensing of this housing pose data may beperformed by a movement sensor (such as a micro-electro-mechanicalsystem (MEMS) accelerometer, gyroscope, and/or inertial measurement unit(IMU)), by an image capture device (such as an optical camera, infra-redcamera, or stereoscopic camera), by a flexible body shape sensor (suchas a fiber Bragg grating (FBG) sensor or elastomeric printed electricalcomponents), by an electromagnetic navigation sensor, or the like; andwill optionally be performed by at least two different sensor types.While external sensor components may be used, the housing pose data mayoptionally be obtained and analyzed using components that are mostly oreven entirely contained within the hand-held housing (for example, usingindoor navigation technologies developed for smart phones). This housingpose data may optionally be combined with signals from a simple multipledegree of freedom input device (such as a joystick or the like) mountedto the housing to provide effective control over more than 6articulation degrees of freedom (sometimes called degrees of freedom injoint space) with a single hand of the user.

Embodiments provided herein may use balloon-like structures to effectarticulation of the elongate catheter or other body. The term“articulation balloon” may be used to refer to a component which expandson inflation with a fluid and is arranged so that on expansion theprimary effect is to cause articulation of the elongate body. Note thatthis use of such a structure is contrasted with a conventionalinterventional balloon whose primary effect on expansion is to causesubstantial radially outward expansion from the outer profile of theoverall device, for example to dilate or occlude or anchor in a vesselin which the device is located. Independently, articulated medialstructures described herein will often have an articulated distalportion, and an unarticulated proximal portion, which may significantlysimplify initial advancement of the structure into a patient usingstandard catheterization techniques.

The catheter bodies (and many of the other elongate flexible bodies thatbenefit from the inventions described herein) will often be describedherein as having or defining an axis, such that the axis extends alongthe elongate length of the body. As the bodies are flexible, the localorientation of this axis may vary along the length of the body, andwhile the axis will often be a central axis defined at or near a centerof a cross-section of the body, eccentric axes near an outer surface ofthe body might also be used. It should be understood, for example, thatan elongate structure that extends “along an axis” may have its longestdimension extending in an orientation that has a significant axialcomponent, but the length of that structure need not be preciselyparallel to the axis. Similarly, an elongate structure that extends“primarily along the axis” and the like will generally have a lengththat extends along an orientation that has a greater axial componentthan components in other orientations orthogonal to the axis. Otherorientations may be defined relative to the axis of the body, includingorientations that are transvers to the axis (which will encompassorientation that generally extend across the axis, but need not beorthogonal to the axis), orientations that are lateral to the axis(which will encompass orientations that have a significant radialcomponent relative to the axis), orientations that are circumferentialrelative to the axis (which will encompass orientations that extendaround the axis), and the like. The orientations of surfaces may bedescribed herein by reference to the normal of the surface extendingaway from the structure underlying the surface. As an example, in asimple, solid cylindrical body that has an axis that extends from aproximal end of the body to the distal end of the body, the distal-mostend of the body may be described as being distally oriented, theproximal end may be described as being proximally oriented, and thesurface between the proximal and distal ends may be described as beingradially oriented. As another example, an elongate helical structureextending axially around the above cylindrical body, with the helicalstructure comprising a wire with a square cross section wrapped aroundthe cylinder at a 20 degree angle, might be described herein as havingtwo opposed axial surfaces (with one being primarily proximallyoriented, one being primarily distally oriented). The outermost surfaceof that wire might be described as being oriented exactly radiallyoutwardly, while the opposed inner surface of the wire might bedescribed as being oriented radially inwardly, and so forth.

Some or all of the systems described herein may benefit fromorientational alignment between the input and output structures. As theterm is used herein, orientational alignment between an input (such as ajoystick moveable along a first movement command axis, a housingmovement axis, or the like) and an output (such as a corresponding firstlateral articulation axis of an articulated catheter or the axis of thecatheter adjacent the distal end) encompasses but does not require thatthe corresponding input and the output axes be exactly parallel.Functionally, input and output reference frames that are within a rangeof angles from parallel can be perceived by a majority of system usershaving a threshold amount of experience as generating output movementsthat correspond sufficiently to input movements to provide efficienteye/hand coordination, and input/output angular relationships that arewithin such a range are considered herein to have orientationalalignment. Note that the range of effectively orientationally alignedangles may vary among differing articulation axes (i.e., pitch, yaw,roll, up/down, left/right, in/out), and the acceptable angular offsetsmay be smaller for input/output systems having more degrees of freedom.Regardless, while the desirable angular range(s) for a particular usermay be subjective, whether a particular input/output orientationalrelationship is within an effectively aligned angular range for mostusers in a typical population for a particular system may be empiricallyquantified based on statistical analysis of user times to performappropriate benchmark tasks, with acceptable orientations resulting inmost user task times within a desired threshold (for example, 10%, 20%,40%, or the like) of those associated with a parallel input/outputrelationship.

Referring first to FIG. 1, a first exemplary catheter system 1 andmethod for its use are shown. A physician or other system user Uinteracts with catheter system 1 so as to perform a therapeutic and/ordiagnostic procedure on a patient P, with at least a portion of theprocedure being performed by advancing a catheter 3 into a body lumenand aligning an end portion of the catheter with a target tissue of thepatient. More specifically, a distal end of catheter 3 is inserted intothe patient through an access site A, and is advanced through one of thelumen systems of the body (typically the vasculature network) while userU guides the catheter with reference to images of the catheter and thetissues of the body obtained by a remote imaging system.

In this exemplary embodiment, catheter system 1 may be used in a manualmode during a portion of the procedure. In the manual mode, user U canhelp advance, retract, or position the distal end of the catheter withinthe patient by manually grasping the exposed catheter shaft near thepatient and moving the catheter shaft relative to the patient, oftenwhile also holding an introducer sheath of the assembly to prevent theintroducer sheath from being dislodged. Alternatively, user U may graspa proximal or housing affixed to the proximal end of the catheter bodywith one hand (for example, using a forefinger and/or a thumb tointermittently adjust a steering bend angle or the like, with the restof the hand supporting the housing), and may manipulate the catheterrelative to the introducer with the other hand (for example, with thethumb and forefinger grasping and manipulating the catheter body and theremaining fingers holding the introducer in place). The input forpowered movement of catheter system 1 may to some extent mimic thesemanual manipulations so as to facilitate driving the catheter in anautomated articulation mode, and also to facilitate the transitionsbetween manual and automated articulation modes. For example, user U maygrasp a first exposed portion of assembly 5 a using fingers of a firsthand H1 (to inhibit introducer sheath displacement), and may also graspand manipulate another exposed portion of assembly 5 a near the patientusing fingers of a second hand H2. Alternatively, the user may grasp theintroducer and adjacent catheter with one hand, and may move a proximalhousing or handle of the catheter with the other. In either case,relative movements of these grasped components can be used as inputmovement commands to the automated catheter system, with those relativemovements being reminiscent of the hand movements used in the manualmode (and of the hand movements used for manipulation of known manualcatheter systems). While often described herein with reference tomanipulation of a catheter, these devices, system, and methods will alsobe well suited for manipulation of other medical structures includingguidewires and the like, and may also be used for manipulation ofnon-medical structures such as industrial endoscopes or boroscopes andthe like.

Exemplary catheter system 1 will often be introduced into patient Pthrough one of the major blood vessels of the leg, arm, neck, or thelike. A variety of known vascular access techniques may also be used, orthe system may alternatively be inserted through a body orifice orotherwise enter into any of a number of alternative body lumens. Theimaging system will generally include an image capture system 7 foracquiring the remote image data and a display D for presenting images ofthe internal tissues and adjacent catheter system components. Suitableimaging modalities may include fluoroscopy, computed tomography,magnetic resonance imaging, ultrasonography, combinations of two or moreof these, or others.

Catheter 3 may be used by user U in different modes during a singleprocedure, including two or more of a manual manipulation mode, anautomated and powered shape-changing mode, and a combination mode inwhich the user manually moves the proximal end while a computerarticulates the distal portion. More specifically, at least a portion ofthe distal advancement of catheter 3 within the patient may be performedin a manual mode, with system user U manually manipulating the exposedproximal portion of the catheter relative to the patient using hands H1,H2. Catheter 3 may, for example, be manually advanced over a guidewire,using either over-the-wire or rapid exchange techniques. Catheter 3 mayalso be self-guiding during manual advancement (so that for at least aportion of the advancement of catheter 3, a distal tip of the cathetermay guide manual distal advancement). Automated lateral deflection of adistal portion of the catheter may impose a desired distal steering bendprior to a manual movement, such as near a vessel bifurcation, followedby manual movement through the bifurcation. In addition to such manualmovement modes, catheter system 1 may also have a 3-D automated movementmode using computer controlled articulation of at least a portion of thelength of catheter 3 disposed within the body of the patient to changethe shape of the catheter portion, often to advance or position thedistal end of the catheter. Movement of the distal end of the catheterwithin the body will often be provided per real-time or near real-timemovement commands input by user U, with the portion of the catheter thatchanges shape optionally being entirely within the patient so that themovement of the distal portion of the catheter is provided withoutmovement of a shaft or cable extending through the access site. Stillfurther modes of operation of system 1 may also be implemented,including concurrent manual manipulation with automated articulation,for example, with user U manually advancing the proximal shaft throughaccess site A while computer-controlled lateral deflections and/orchanges in stiffness over one or more axial segments along a distalportion of the catheter help the distal end follow a desired path and/orreduce resistance to the axial movement.

Referring next to FIG. 1-1 components which may be included in or usedwith catheter system 1 or catheter 3 (described above) can be more fullyunderstood with reference to an alternative catheter system 10 and itscatheter 12. Cather 12 generally includes an elongate flexible catheterbody and is detachably coupled to a handle 14, preferably by aquick-disconnect coupler 16. Handle 14 (and similar proximal handleshaving steering input capabilities) may be used in place of or togetherwith assembly 5 a (also described above), so that components of suchhandles can be included in the user interface of the catheter system.Catheter body 12 has an axis 30, and an input 18 of handle 14 can bemoved by a user so as to locally alter the axial bending characteristicsalong catheter body 12, often for variably articulating an actuatedportion 20 of the catheter body. Catheter body 12 will often have aworking lumen 26 into or through which a therapeutic and/or diagnostictool may be advanced from a proximal port 28 of handle 14. Alternativeembodiments may lack a working lumen, may have one or more therapeuticor diagnostic tools incorporated into the catheter body near or alongactuated portion 20, may have a sufficiently small outer profile tofacilitate use of the body as a guidewire, may carry a tool or implantnear actuated portion 20 or near distal end 26, or the like. Inparticular embodiments, catheter body 12 may support a therapeutic ordiagnostic tool 8 proximal of, along the length of, and/or distal ofactuated portion 20. Alternatively, a separate elongate flexiblecatheter body may be guided distally to a target site once catheter body20 has been advanced (with the elongate body for such uses often takingthe form and use of a guidewire or guide catheter).

The particular tool or tools included in, advanceable over, and/orintroducible through the working lumen of catheter body 20 may includeany of a wide range of therapeutic and/or treatment structures. Examplesinclude cardiovascular therapy and diagnosis tools (such as angioplastyballoons, stent deployment balloons or other devices, atherectomydevices, tools for detecting, measuring, and/or characterizing plaque orother occlusions, tools for imaging or other evaluation of, and/ortreatment of, the coronary or peripheral arteries, structural hearttools (including prostheses or other tools for valve procedures, foraltering the morphology of the heart tissues, chambers, and appendages,and the like), tools for electrophysiology mapping or ablation tools,and the like); stimulation electrodes or electrode implantation tools(such as leads, lead implant devices, and lead deployment systems,leadless pacemakers and associated deployments systems, and the like);neurovascular therapy tools (including for accessing, diagnosis and/ortreatment of hemorrhagic or ischemic strokes and other conditions, andthe like); gastrointestinal and/or reproductive procedure tools (such ascolonoscopic diagnoses and intervention tools, transurethral proceduretools, transesophageal procedure tools, endoscopic bariatric proceduretools, etc.); hysteroscopic and/or falloposcopic procedure tools, andthe like; pulmonary procedure tools for therapies involving the airwaysand/or vasculature of the lungs; tools for diagnosis and/or treatment ofthe sinus, throat, mouth, or other cavities, and a wide variety of otherendoluminal therapies and diagnoses structures. Such tools may make useof known surface or tissue volume imaging technologies (includingimaging technologies such as 2-D or 3-D cameras or other imagingtechnologies; optical coherence tomography technologies; ultrasoundtechnologies such as intravascular ultrasound, transesophogealultrasound, intracardiac ultrasound, Doppler ultrasound, or the like;magnetic resonance imaging technologies; and the like), tissue or othermaterial removal, incising, and/or penetrating technologies (such arotational or axial atherectomy technologies; morcellation technologies;biopsy technologies; deployable needle or microneedle technologies;thrombus capture technologies; snares; and the like), tissue dilationtechnologies (such as compliant or non-compliant balloons, plasticallyor resiliently expandable stents, reversibly expandable coils, braids orother scaffolds, and the like), tissue remodeling and/or energy deliverytechnologies (such as electrosurgical ablation technologies, RFelectrodes, microwave antennae, cautery surfaces, cryosurgicaltechnologies, laser energy transmitting surfaces, and the like), localagent delivery technologies (such as drug eluting stents, balloons,implants, or other bodies; contrast agent or drug injection ports;endoluminal repaving structures; and the like), implant and prosthesisdeploying technologies, anastomosis technologies and technologies forapplying clips or sutures, tissue grasping and manipulationtechnologies; and/or the like. In some embodiments, the outer surface ofthe articulation structure may be used to manipulate tissues directly.Non-medical embodiments may similarly have a wide range of tools orsurfaces for industrial, assembly, imaging, manipulation, and otheruses.

Addressing catheter body 12 of system 10 (and particularly articulationcapabilities of actuated portion 20) in more detail, the catheter bodygenerally has a proximal end 22 and a distal end 24 with axis 30extending between the two. As can be understood with reference to FIG.2, catheter body 12 may have a short actuated portion 20 of about 3diameters or less, but will often have an elongate actuated portion 20extending intermittently or continuously over several diameters of thecatheter body (generally over more than 3 diameters, often over morethan 10 diameters, in many cases over more than 20 diameters, and insome embodiments over more than 40 diameters). A total length ofcatheter body 12 (or other flexible articulated bodies employing theactuation components described herein) may be from 5 to 500 cm, moretypically being from 15 to 260 cm, with the actuated portion optionallyhaving a length of from 1 to 150 cm (more typically being 2 to 20 cm)and an outer diameter of from 0.65 mm to 5 cm (more typically being from1 mm to 2 cm). Outer diameters of guidewire embodiments of the flexiblebodies may be as small as 0.012″ though many embodiments may be morethan 2 Fr, with catheter and other medical embodiments optionally havingouter diameters as large as 34 French or more, and with industrialrobotic embodiments optionally having diameters of up to 1″ or more.Exemplary catheter embodiments for structural heart therapies (such astrans-catheter aortic or mitral valve repair or implantation, leftatrial appendage closure, and the like) may have actuated portions withlengths of from 3 to 30 cm, more typically being from 5 to 25 cm, andmay have outer profiles of from 10 to 30 Fr, typically being from 12 to18 Fr, and ideally being from 13 to 16 Fr. Electrophysiology therapycatheters (including those having electrodes for sensing heart cyclesand/or electrodes for ablating selected tissues of the heart) may havesizes of from about 5 to about 12 Fr, and articulated lengths of fromabout 3 to about 30 cm. A range of other sizes might also be implementedfor these or other applications.

Referring now to FIGS. 1A, 1B, and 1C, system 10 may be configured toarticulate actuated portion 20. Articulation will often allow movementcontinuously throughout a range of motion, though some embodiments mayprovide articulation in-part or in-full by selecting from among aplurality of discrete articulation states. Catheters having opposedaxial extension and contraction actuators are described herein that maybe particularly beneficial for providing continuous controlled andreversible movement, and can also be used to modulate the stiffness of aflexible structure. These continuous and discrete systems share manycomponents (and some systems might employ a combination of bothapproaches). First addressing the use of a discrete state system, FIG.1A, system 10 can, for example, increase an axial length of actuatedportion 20 by one or more incremental changes in length ΔL. An exemplarystructure for implementation of a total selectable increase in length ΔLcan combine a plurality of incremental increases in length ΔL=ΔL₁+ΔL₂+ .. . ), as can be understood with reference to FIG. 4D. As shown in FIGS.1B and 1C, system 10 may also deflect distal end 24 to a first bentstate having a first bend angle 31 between unarticulated axis 30 and anarticulated axis 30′ (as shown schematically in FIG. 1B), or to a secondbent state having a total bend angle 33 (between articulated axis 30 andarticulated axis 30″), with this second bend angle being greater thanthe first bend angle (as shown schematically in FIG. 1C). An exemplarystructure for combining multiple discrete bend angle increments to forma total bend angle 33 can be understood with reference to FIG. 4C.Regardless, the additional total cumulative bend angle 33 may optionallybe implemented by imposing the first bend 31 (of FIG. 1B) as a firstincrement along with one or more additional bend angle increments 35.The incremental changes to actuated portion 20 may be provided by fullyinflating and/or deflating actuation balloons of the catheter system.Bend capabilities may be limited to a single lateral orientation, butwill more typically be available in different lateral orientations, mosttypically in any of 3 or 4 orientations (for example, using balloonspositioned along two pairs of opposed lateral axes, sometimes referredto as the +X, −X, +Y and −Y orientations), and by combining differentbend orientations, in intermediate orientations as well. Continuouspositioning may be implemented using similar articulation structures bypartially inflating or deflating balloons or groups of balloons.

System 10 may also be configured to provide catheter 12 with any of aplurality of discrete alternative total axial lengths. As with the bendcapabilities, such length actuation may also be implemented by inflatingballoons of a balloon array structure. To provide articulation with thesimple balloon array structures described herein, each actuation may beimplemented as a combination of discrete, predetermined actuationincrements (optionally together with one or more partial or modulatedactuation) but may more often be provided using modulated or partialinflation of balloons.

Referring now to FIGS. 1-1 and 2, embodiments of articulation system 10will move the distal end 24 of catheter 12 toward a desired positionand/or orientation in a workspace relative to a base portion 21, withthe base portion often being adjacent to and proximal of actuatedportion 20. Note that such articulation may be relatively (or evencompletely) independent of any bending of catheter body 12 proximal ofbase portion 21. The location and orientation of proximal base 21(relative to handle 14 or to another convenient fixed or movablereference frame) may be identified, for example, by including knowncatheter position and/or orientation identification systems in system10, by including radiopaque or other high-contrast markers andassociated imaging and position and/or orientation identifying imageprocessing software in system 10, by including a flexible body statesensor system along the proximal portion of catheter body 12, byforegoing any flexible length of catheter body 12 between proximalhandle 14 and actuated portion 20, or the like. A variety of differentdegrees of freedom may be provided by actuated portion 20. Exemplaryembodiments of articulation system 10 may allow, for example, distal end24 to be moved with 2 degrees of freedom, 3 degrees of freedom, 4degrees of freedom, 5 degrees of freedom, or 6 degrees of freedomrelative to base portion 21. The number of kinematic degrees of freedomof articulated portion 20 may be much higher in some embodiments,particularly when a number of different alternative subsets of theballoon array could potentially be in different inflation states to givethe same resulting catheter tip and/or tool position and orientation.

Note that the elongate catheter body 12 along and beyond actuatedportion 20 may (and often should) remain flexible before, during, andafter articulation, so as to avoid inadvertently applying lateral and/oraxial forces to surrounding tissues that are beyond a safe threshold.Nonetheless, embodiments of the systems described herein may locally andcontrollable increase a stiffness of one or more axial portions ofcatheter body 12, along actuated portion 20, proximal of actuatedportion 20, and/or distal of actuated portion 20. Such selectivestiffening of the catheter body may be implemented with or withoutactive articulation capabilities, may extend along one or more axialportion of catheter body 12, and may alter which portions are stiffenedand which are more flexible in response to commands from the user,sensor input (optionally indicating axial movement of the catheter), orthe like.

As shown in FIG. 2, actuated portion 20 may comprise an axial series of2 or more (and preferably at least 3) actuatable sub-portions orsegments 20′, 20″, 20′″, with the segments optionally being adjacent toeach other, or alternatively separated by relatively short (less than 10diameters) and/or relatively stiff intermediate portions of catheter 12.Each sub-portion or segment may have an associated actuation array, withthe arrays working together to provide the desired overall cathetershape and degrees of freedom to the tip or tool. At least 2 of thesub-portions may employ similar articulation components (such as similarballoon arrays, similar structural backbone portions, similar valvesystems, and/or similar software). Commonality may include the use ofcorresponding actuation balloon arrays, but optionally with thecharacteristics of the individual actuation balloons of the differentarrays and the spacing between the locations of the arrays varying forany distal tapering of the catheter body. There may be advantages to theuse of differentiated articulation components, for example, withproximal and distal sub portions, 20′, 20′″ having similar structuresthat are configured to allow selective lateral bending with at least twodegrees of freedom, and intermediate portion 20″ being configured toallow variable axial elongation. In many embodiments, however, at leasttwo (and preferably all) segments are substantially continuous and sharecommon components and geometries, with the different segments havingseparate fluid channels and being separately articulatable but eachoptionally providing similar movement capabilities.

For those elongate flexible articulated structures described herein thatinclude a plurality of axial segments, the systems will often determineand implement each commanded articulation of a particular segment as asingle consistent articulation toward a desired segment shape state thatis distributed along that segment. In some exemplary embodiments, thenominal or resting segment shape state may be constrained to a 3 DOFspace (such as by continuous combinations of two transverse lateralbending orientations and an axial (elongation) orientation in an X-Y-Zwork space). In some of the exemplary embodiments described herein(including at least some of the helical extension/contractionembodiments), lateral bends along a segment may be at leastapproximately planar when the segment is in or near a design axiallength configuration (such as at or near the middle of the axial or Zrange of motion), but may exhibit a slight but increasing off-planetwisting curvature as the segment moves away from that designconfiguration (such as near the proximal and/or distal ends of the axialrange of motion). The off-plane bending may be repeatably accounted forkinematically by determining the changes in lateral orientation ofeccentric balloons resulting from winding and unwinding of helicalstructures supporting those balloons when the helical structuresincrease and decrease in axial length. For example, a segment may becommanded (as part of an overall desired pose or movement) to bend in a−Y orientation with a 20 degree bend angle. If the bend is to occur at adesign axial length (such as at the middle of the axial range ofmotion), and assuming balloons (or opposed balloon pairs) at 4 axialbend locations can be used to provide the commanded bend, the balloons(or balloon pairs) may each be inflated or deflated to bend the segmentby about 5 degrees (thereby providing a total bend of 5*4 or 20 degrees)in the −Y orientation. If the same bend is to be combined with axiallengthening of the segment to the end of its axial range of motion, theprocessor may determine that the segment may exhibit some twist (say 2degrees) so that there would be a slight +X component to the commandedbend, so that the processor may compensate for the twist by commanding acorresponding −X bend component, or by otherwise compensating in thecommand for another segment of the flexible body.

Referring to FIGS. 3 and 5, catheter body 12 of system 10 includes anactuation array structure 32 mounted to a structural skeleton (here inthe form of a helical coil 34). Exemplary balloon array 32 includesfluid expandable structures or balloons 36 distributed at balloonlocations along a flexible substrate 38 so as to define an M×N array, inwhich M is an integer number of balloons distributed about acircumference 50 of catheter 12 at a given location along axis 30, and Nrepresents an integer number of axial locations along catheter 12 havingactuation balloons. Circumferential and axial spacing of the arrayelement locations will generally be known, and will preferably beregular. This first exemplary actuation array includes a 4×4 array for atotal of 16 balloons; alternative arrays may be from 1 X 2 arrays for atotal of 2 balloons to 8×200 arrays for a total of 1600 balloons (orbeyond), more typically having from 3×3 to 6×20 arrays. While balloonarrays of 1×N may be provided (particularly on systems that rely onrotation of the catheter body to orient a bend), M will more typicallybe 2 or more, more often being from 3 to 8, and preferably being 3 or 4.Similarly, while balloon arrays of M×1 may be provided to allowimposition of a single bend increment at a particular location in any ofa number of different desired lateral orientations, array 32 will moretypically have an N of from 2 to 200, often being from 3 to 20 or 3 to100. In contraction/expansion embodiments described below, multiplearrays may be provided with similar M×N arrays mounted in opposition.Not all array locations need have inflatable balloons, and the balloonsmay be arranged in more complex arrangements, such as with alternatingcircumferential numbers of balloons along the axis, or with varying oralternating separation between balloons along the axial length of thearray.

The balloons of a particular segment or that are mounted to a commonsubstrate may be described as forming an array, with the actuationballoon array structure optionally being used as a sub-array in amulti-segment or opposed articulation system. The combined sub-arraystogether may form an array of the overall device, which may also bedescribed simply as an array or optionally an overall or combined array.Exemplary balloon arrays along a segment or sub-portion of articulatedportion 20 include 1×8, 1×12, and 1×16 arrays for bending in a singledirection (optionally with 2, 3, 4, or even all of the balloons of thesegment in fluid communication with a single common inflation lumen soas to be inflated together) and 4×4, 4×8, and 4×12 arrays for X-Ybending (with axially aligned groups of 2-12 balloons coupled with 4 ormore common lumens for articulation in the +X, −X, +Y, and −Yorientations). Exemplary arrays for each segment having the opposedextension/retraction continuous articulation structures described hereinmay be in the form of a 3×2N, 3×3N, 4×2N, or 4×3N balloons arrays, forexample, 3×2, 3×4, 3×6, 3×8, 3×10, 3×12, 3×14, and 3×16 arrays with 6 to48 balloons, with the 3 lateral balloon orientations separated by 120degrees about the catheter axis. Extension balloons will often beaxially interspersed with contraction balloons along each lateralorientation, with separate 3 X N arrays being combined together in a3×2N extension/contraction array for the segment, while two extensionballoons may be positioned axially between each contraction balloon for3×3N arrangements. The contraction balloons may align axially and/or bein plane with the extension balloons they oppose, though it may beadvantageous in some embodiments to arrange opposed balloons offset froma planer arrangement, so that (for example) two balloons of one typebalance one balloon of the other, or vice versa. The extension balloonsalong each orientation of the segment may share a common inflation fluidsupply lumen while the contraction balloons of the segment for eachorientation similarly share a common lumen (using 6 fluid supply lumensper segment for both 3×2N and 3×3N arrays). An extension/contractioncatheter may have from 1 to 8 such segments along the articulatedportion, more typically from 1 to 5 segments, and preferably being 2 to4 segments. Other medical and non-medical elongate flexible articulatedstructures may have similar or more complex balloon articulation arrays.

As can be seen in FIGS. 3, 4A, 4B, and 4C, the skeleton will often(though not always) include an axial series of loops 42. When the loopsare included in a helical coil 34, the coil may optionally be biased soas to urge adjacent loops 42 of the coil 34 toward each other. Suchaxially compressive biasing may help urge fluid out and deflate theballoons, and may by applied by other structures (inner and/or outersheath(s), pull wires, etc.) with or without helical compression. Axialengagement between adjacent loops (directly, or with balloon walls orother material of the array between loops) can also allow compressiveaxial forces to be transmitted relatively rigidly when the balloons arenot inflated. When a particular balloon is fully inflated, axialcompression may be transmitted between adjacent loops by the fullyinflated balloon wall material and by the fluid within the balloons.Where the balloon walls are non-compliant, the inflated balloons maytransfer these forces relatively rigidly, though with some flexing ofthe balloon wall material adjacent the balloon/skeleton interface. Rigidor semi-rigid interface structures which distribute axial loads across abroader balloon interface region may limit such flexing. Axial tensionforces (including those associated with axial bending) may be resistedby the biasing of the skeleton (and/or by other axial compressivestructures). Alternative looped skeleton structures may be formed, forexample, by cutting hypotube with an axial series of lateral incisionsacross a portion of the cross-section from one or more lateralorientations, braided metal or polymer elements, or the like. Non-loopedskeletons may be formed using a number of alternative known rigid orflexible robotic linkage architectures, including with structures basedon known soft robot structures. Suitable materials for coil 34 or otherskeleton structures may comprise metals such as stainless steel, springsteel, superelastic or shape-memory alloys such as Nitinol™ alloys,polymers, fiber-reinforced polymers, high-density or ultrahigh-densitypolymers, or the like.

When loops are included in the skeleton, actuation array 32 can bemounted to the skeleton with at least some of the balloons 36 positionedbetween two adjacent associated loops 42, such as between the loops ofcoil 34. Referring now to FIG. 4C, an exemplary deflated balloon 36 i islocated between a proximally adjacent loop 42 i and a distally adjacentloop 42 ii, with a first surface region of the balloon engaging adistally oriented surface of proximal loop 34 i, and a second surfaceregion of the balloon engaging a proximally oriented surface of distalloop 42 ii. The walls of deflated balloon 36 i have some thickness, andthe proximal and distal surfaces of adjacent loops 42 i and 42 iimaintain a non-zero axial deflated offset 41 between the loops. Axialcompression forces can be transferred from the loops through the solidballoon walls. Alternative skeletal structures may allow the loops toengage directly against each other so as to have a deflated offset ofzero and directly transmit axial compressive force, for example byincluding balloon receptacles or one or more axial protrusions extendingfrom one or both loops circumferentially or radially beyond the balloonand any adjacent substrate structure. Regardless, full inflation of theballoon will typically increase the separation between the adjacentloops to a larger full inflation offset 41′. The simplified lateralcross-sections of FIGS. 4B, 4C, and 4D schematically show a directinterface engagement between a uniform thickness thin-walled balloon anda round helical coil loop. Such an interface may result in relativelylimited area of the balloon wall engaging the coil and associateddeformation under axial loading. Alternative balloon-engaging surfaceshapes along the coils (often including locally increased convex radii,locally flattened surfaces, and/or local concave balloon receptacles)and/or along the coil-engaging surfaces of the balloon (such as bylocally thickening the balloon wall to spread the engagement area),and/or providing load-spreading bodies between the balloons and thecoils may add axial stiffness. A variety of other modifications to theballoons and balloon/coil interfaces may also be beneficial, includingadhesive bonding of the balloons to the adjacent coils, including foldsor material so as to inhibit balloon migration, and the like.

Inflation of a balloon can alter the geometry along catheter body 12,for example, by increasing separation between loops of a helical coil soas to bend axis 30 of catheter 12. As can be understood with referenceto FIGS. 1B, 1C and 4-4C, selectively inflating an eccentric subset ofthe balloons can variably alter lateral deflection of the catheter axis.As can be understood with reference to FIGS. 1A, 4, and 4D, inflation ofall (or an axisymmetric subset) of the balloons may increase an axiallength of the catheter structure. Inflating subsets of the balloons thathave a combination of differing lateral orientations and axial positionscan provide a broad range of potential locations and orientations of thecatheter distal tip 26, and/or of one or more other locations along thecatheter body (such as where a tool is mounted).

Some or all of the material of substrate 38 included in actuation array32 will often be relatively inelastic. It may, however, be desirable toallow the skeleton and overall catheter to flex and/or elongate axiallywith inflation of the balloons or under environmental forces. Hence,array 32 may have cutouts 56 so as to allow the balloon array to moveaxially with the skeleton during bending and elongation. The arraystructure could alternatively (or in addition) be configured for sucharticulation by having a serpentine configuration or a helical coiledconfiguration. Balloons 36 of array 32 may include non-compliant balloonwall materials, with the balloon wall materials optionally being formedintegrally from material of the substrate or separately. Note thatelastic layers or other structures may be included in the substrate foruse in valves and the like, and that some alternative balloons mayinclude elastic and/or semi-compliant materials.

Referring to FIGS. 3, 4A, and 5, substrate 38 of array 32 is laterallyflexible so that the array can be rolled or otherwise assume acylindrical configuration when in use. The cylindrical array may becoaxially mounted to (such as being inserted into or radially outwardlysurrounding) the helical coil 34 or other structural backbone of thecatheter. The cylindrical configuration of the array will generally havea diameter that is equal to or less than an outer diameter of thecatheter. The opposed lateral edges of substrate 38 may be separated bya gap as shown, may contact each other, or may overlap. Contacting oroverlapping edges may be affixed together (optionally so as to help sealthe catheter against radial fluid flow) or may accommodate relativemotion (so as to facilitate axil flexing). In some embodiments, lateralrolling or flexing of the substrate to form the cylindricalconfiguration may be uniform (so as to provide a continuous lateralcurve along the major surfaces), while in other embodiments intermittentaxial bend regions of the substrate may be separated by axially elongaterelatively flat regions of the substrate so that a cylindrical shape isapproximated by a prism-like arrangement (optionally so as to limitbending of the substrate along balloons, valves, or other arraycomponents).

It will often (though not always) be advantageous to form and/orassemble one or more components of the array structure in a flat,substantially planar configuration (and optionally in a linearconfiguration as described below). This may facilitate, for example,partial or final formation of balloons 36 on substrate 38, oralternatively, attachment of pre-formed balloons to the substrate. Theflat configuration of the substrate may also facilitate the use of knownextrusion or microfluidic channel fabrication techniques to providefluid communication channels 52 so as to selectively couple the balloonswith a fluid inflation fluid source or reservoir 54, and the like. Stillfurther advantages of the flat configuration of the substrate mayinclude the use of electrical circuit printing techniques to fabricateelectrical traces and other circuit components, automated 3-D printingtechniques (including additive and/or removal techniques) for formingvalves, balloons, channels, or other fluid components that will besupported by substrate 38, and the like. When the substrate is in arolled, tubular, or flat planar configuration, the substrate willtypically have a first major surface 62 adjacent balloons 36, and asecond major surface 64 opposite the first major surface (with firstmajor surface 62 optionally being a radially inner or outer surface andsecond major surface 64 being a radially outer or inner surface,respectively, in the cylindrical configuration). To facilitate flexingsubstrate 38 and array 32 into the rolled configuration, relief cuts orchannels may be formed extending into the substrate from the firstand/or second major surfaces, or living hinge regions may otherwise beprovided between relatively more rigid portions of the substrate. Tofurther avoid deformation of the substrate adjacent any valves or othersensitive structures, local stiffening reinforcement material may beadded, and/or relief cuts or apertures may be formed partiallysurrounding the valves. In some embodiments, at least a portion of thearray components may be formed or assembled with the substrate at leastpartially in a cylindrical configuration, such as by bonding layers ofthe substrate together while the substrate is at least locally curved,forming at least one layer of the substrate as a tube, selectivelyforming cuts in the substrate (optionally with a femtosecond,picosecond, or other laser) to form fluid, circuit, or other componentsor allow for axial flexing and elongation (analogous to cutting a stentto allow for axial flexing and radial expansion) and/or to form at leastsome of the channels, and bonding the layers together after cutting.

As can be understood with reference to FIGS. 5 and 6, substrate 38 ofarray 32 may include one or more layers of flexible substrate material.The substrate layers may comprise known flexible and/or rigidmicrofluidic substrate materials, such as polydimethylsiloxane (PDMS),polyimide (PI), polyethylene (PE) and other polyolefins, polystyrene(PS), polyethylene terephthalate (PET), polypropylene (PP),polycarbonate (PC), nanocomposite polymer materials, glass, silicon,cyclic olefin copolymer (COC), polymethyl methacrylate (PMMA),polyetheretherketone (PEEK), polyester, polyurethane (PU), and/or thelike. These and still further known materials may be included in othercomponents of actuation array 32, including known polymers for use inballoons (which will often include PET, PI, PE, polyether block amide(PEBA) polymers such as PEBAX™ polymers, nylons, urethanes, polyvinylchloride (PVC), thermoplastics, and/or the like for non-compliantballoons; or silicone, polyurethane, semi-elastic nylons or otherpolymers, latex, and/or the like for compliant or semi-compliantballoons). Additional polymers than may be included in the substrateassembly may include valve actuation elements (optionally includingshape memory alloy structures or foils; phase-change actuator materialssuch as paraffin or other wax, electrical field sensitive hydrogels,bimetallic actuators, piezoelectric structures, dielectric elastomeractuator (DEA) materials, or the like). Hence, while some embodimentsmay employ homogenous materials for actuation array 32, many arrays andsubstrate may instead be heterogeneous.

Fortunately, techniques for forming and assembling the components foractuation array 32 may be derived from a number of recent (andrelatively widely-reported) technologies. Suitable techniques forfabricating channels in substrate layer materials may include lasermicromachining (optionally using femtosecond or picosecond lasers),photolithography techniques such as dry resist technologies, embossing(including hot roller embossing), casting or molding, xerographictechnologies, microthermoforming, stereolithography, 3-D printing,and/or the like. Suitable 3-D printing technologies that may be used toform circuitry, valves, sensors, and the like may includestereolithography, digital light processing, laser sintering or melting,fused deposition modeling, inkjet printing, selective depositionlamination, electron beam melting, or the like. Assembly of thecomponents of actuation array 32 may make use of thermal or adhesivebonding between layers and other components, though laser, ultrasound,or other welding techniques; microfasteners, or the like may also beused. Electrical element fabrication of conductive traces, actuation,signal processor, and/or sensor components carried by substrate 38 may,for example, use ink-jet or photolithography techniques, 3-D printing,chemical vapor deposition (CVD) and/or more specific variants such asinitiated chemical vapor deposition (iCVD), robotic microassemblytechniques, or the like, with the electrical traces and other componentsoften comprising inks and other materials containing metals (such assilver, copper, or gold) carbon, or other conductors. Many suitablefabrication and assembly techniques have been developed duringdevelopment of microfluidic lab-on-a-chip or lab-on-a-foil applications.Techniques for fabricating medical balloons are well developed, and mayoptionally be modified to take advantage of known high-volume productiontechniques (optionally including those developed for fabricating bubblewrap, for corrugating extruded tubing, and the like). Note that whilesome embodiments of the actuation array structures described herein mayemploy fluid channels sufficiently small for accurately handling ofpicoliter or nanoliter fluid quantities, other embodiments will includechannels and balloons or other fluid-expandable bodies that utilize muchlarger flows so as to provide desirable actuation response times.Balloons having at least partially flexible balloon walls may provideparticular advantages for the systems described herein, but alternativerigid fluid expandable bodies such as those employing pistons or otherpositive displacement expansion structures may also find use in someembodiments.

The structures of balloons 36 as included in actuation array 32 may beformed of material integral with other components of the array, or maybe formed separately and attached to the array. Balloons 36 may beformed from or attached to a first sheet of substrate material that canbe bonded or otherwise affixed to another substrate layer or layers. Thematerial of the balloon layer may optionally cover portions of thechannels directly, or may be aligned with apertures that open through anintermediate substrate layer surface between the channels and theballoons. Alternative methods for fabricating individual balloons arewell known, and the formed balloons may be affixed to the substrate 38by adhesive bonding. Balloon shapes may comprise relatively simplecylinders or may be somewhat tailored to taper to follow an expandedoffset between loops of a coil, to curve with the cylindrical substrateand/or to engage interface surfaces of the skeleton over a broadersurface area and thereby distribute actuation and environmental loads.Effective diameters of the balloons in the array may range from about0.003 mm to as much as about 2 cm (or more), more typically being in arange from about 0.3 mm to about 2 mm or 5 mm, with the balloon lengthsoften being from about 2 to about 15 times the diameter. Typical balloonwall thicknesses may range from about 0.0002 mm to about 0.004 mm (withsome balloon wall thicknesses being between 0.0002 mm and 0.020 mm), andfull inflation pressures in the balloons may be from about 0.2 to about40 atm, more typically being in a range from about 0.4 to about 30 atm,and in some embodiments being in a range from about 10 to about 30 atm,with high-pressure embodiments operating at pressures in a range as highas 20-45 atm and optionally having burst pressures of over 50 atm.

Referring now to FIG. 5, balloons 36 will generally be inflated using afluid supply system that includes a fluid source 54 (shown here as apressurized single-use cartridge) and one or more valves 90. At leastsome of the valves 90 may be incorporated into the balloon arraysubstrate, with the valves optionally being actuated using circuitryprinted on one or more layers of substrate 38. With or withoutsubstrate-mounted valves that can be used within a patient body, atleast some of the valves may be mounted to housing 14, or otherwisecoupled to the proximal end of catheter 12. Valves 90 will preferably becoupled to channels 52 so as to allow the fluid system to selectivelyinflate any of a plurality of alternative individual balloons or subsetsof balloons 36 included in actuation array 32, under the direction of aprocessor 60. Hence, processor 60 will often be coupled to valves 90 viaconductors, the conductors here optionally including flex circuit traceson substrate 38.

Referring still to FIG. 5, fluid source 54 may optionally comprise aseparate fluid reservoir and a pump for pressurizing fluid from thereservoir, but will often include a simple tank or cartridge containinga pressurized fluid, the fluid optionally being a gas or a gas-liquidmixture. The cartridge will often maintain the fluid at a supplypressure at or above a full inflation pressure range of balloons 36,with the cartridge optionally being gently heated by a resistive heateror the like (not shown) in housing 14 so as to maintain the supplypressure within a desired range in the cartridge during use. Supplypressures will typically exceed balloon inflation pressures sufficientlyto provide balloon inflation times within a target threshold given thepressure loss through channels 52 and valves 90, with typical supplypressures being between 10 and 210 atm, and more typically being between20 and 60 atm. Suitable fluids may include known medical pressurizedgases such as carbon dioxide, nitrogen, oxygen, nitrous oxide, air,known industrial and cryogenic gasses such as helium and/or other inertor noble gasses, refrigerant gases including fluorocarbons, and thelike. Note that the pressurized fluid in the canister can be directedvia channels 52 into balloons 36 for inflation, or the fluid from thecanister (often at least partially a gas) may alternatively be used topressurize a fluid reservoir (often containing or comprising a benignbiocompatible liquid such as water or saline) so that the ballooninflation fluid is different than that contained in the cartridge. Wherea pressurized liquid or gas/liquid mixture flows distally along thecatheter body, enthalpy of vaporization of the liquid in or adjacent tochannels 52, balloons 36, or other tissue treatment tools carried on thecatheter body (such as a tissue dilation balloon, cryogenic treatmentsurface, or tissue electrode) may be used to therapeutically cooltissue. In other embodiments, despite the use of fluids which are usedas refrigerants within the body, no therapeutic cooling may be provided.The cartridge may optionally be refillable, but will often instead havea frangible seal so as to limit re-use.

As the individual balloons may have inflated volumes that are quitesmall, cartridges that are suitable for including in a hand-held housingcan allow more than a hundred, optionally being more than a thousand,and in many cases more than ten thousand or even a hundred thousandindividual balloon inflations, despite the cartridge containing lessthan 10 ounces of fluid, often less than 5 ounces, in most cases lessthan 3 ounces, and ideally less than 1 ounce. Note also that a number ofalternative fluid sources may be used instead of or with a cartridge,including one or more positive displacement pumps (optionally such assimple syringe pumps), a peristaltic or rotary pump, any of a variety ofmicrofluidic pressure sources (such as wax or other phase-change devicesactuated by electrical or light energy and/or integrated into substrate38), or the like. Some embodiments may employ a series of dedicatedsyringe or other positive displacement pumps coupled with at least someof the balloons by channels of the substrate, and/or by flexible tubing.

Referring still to FIG. 5, processor 60 can facilitate inflation of anappropriate subset of balloons 36 of actuation array 32 so as to producea desired articulation. Such processor-derived articulation cansignificantly enhance effective operative coupling of the input 18 tothe actuated portion 20 of catheter body 12, making it much easier forthe user to generate a desired movement in a desired direction or toassume a desired shape. Suitable correlations between input commands andoutput movements have been well developed for teleoperated systems withrigid driven linkages. For the elongate flexible catheters and otherbodies used in the systems described herein, it will often beadvantageous for the processor to select a subset of balloons forinflation based on a movement command entered into a user interface 66(and particularly input 18 of user interface 66), and on a spatialrelationship between actuated portion 20 of catheter 12 and one or morecomponent of the user interface. A number of differing correlations maybe helpful, including orientational correlation, displacementcorrelation, and the like. Along with an input, user interface 66 mayinclude a display showing actuated portion 20 of catheter body 12, andsensor 63 may provide signals to processor 60 regarding the orientationand/or location of proximal base 21. Where the relationship between theinput, display, and sensor are known (such as when they are all mountedto proximal housing 14 or some other common base), these signals mayallow derivation of a transformation between a user interface coordinatesystem and a base coordinate system of actuated portion 20. Alternativesystems may sense or otherwise identify the relationships between thesensor coordinate system, the display coordinate system, and/or theinput coordinate system so that movements of the input result incatheter movement, as shown in the display. Where the sensor comprisesan image processor coupled to a remote imaging system (such as afluoroscopy, MRI, or ultrasound system), high-contrast marker systemscan be included in proximal base 21 to facilitate unambiguousdetermination of the base position and orientation. A battery or otherpower source (such as a fuel cell or the like) may be included inhousing 14 and coupled to processor 60, with the housing and catheteroptionally being used as a handheld unit free of any mechanical tetherduring at least a portion of the procedure. Nonetheless, it should benoted that processor 60 and/or sensor 63 may be wirelessly coupled oreven tethered together (and/or to other components such as a separatedisplay of user interface 66, an external power supply or fluid source,or the like).

Regarding processor 60, sensor 63, user interface 66, and the other dataprocessing components of system 10, it should be understood that thespecific data processing architectures described herein are merelyexamples, and that a variety of alternatives, adaptations, andembodiments may be employed. The processor, sensor, and user interfacewill, taken together, typically include both data processing hardwareand software, with the hardware including an input (such as a joystickor the like that is movable relative to housing 14 or some other inputbase in at least 2 dimensions), an output (such as a medical imagedisplay screen), an image-acquisition device or other sensor, and one ormore processor. These components are included in a processor systemcapable of performing the image processing, rigid-body transformations,kinematic analysis, and matrix processing functionality describedherein, along with the appropriate connectors, conductors, wirelesstelemetry, and the like. The processing capabilities may be centralizedin a single processor board, or may be distributed among the variouscomponents so that smaller volumes of higher-level data can betransmitted. The processor(s) will often include one or more memory orstorage media, and the functionality used to perform the methodsdescribed herein will often include software or firmware embodiedtherein. The software will typically comprise machine-readableprogramming code or instructions embodied in non-volatile media, and maybe arranged in a wide variety of alternative code architectures, varyingfrom a single monolithic code running on a single processor to a largenumber of specialized subroutines being run in parallel on a number ofseparate processor sub-units.

Referring now to FIG. 6, an alternative actuation array and fluid supplysystem are shown schematically. As in the above embodiment, balloons 36are affixed along a major surface of substrate 38, optionally prior torolling the substrate and mounting of the actuation array to theskeleton of the catheter body. In this embodiment, each balloon has anassociated dedicated channel 52 of substrate 38, and also an associatedvalve 90. Processor 60 is coupled with valves 90, and by actuating adesired subset of the valves the associated subset of balloons can beinflated or deflated. In some embodiments, each valve can be associatedwith more than one balloon 36, so that (for example), opening of asingle valve might inflate a plurality (optionally 2, 3, 4, 8, 12, orsome other desired number) of balloons, such as laterally opposedballoons so as to elongate the distal portion of the catheter. In theseor other embodiments, a plurality of balloons (2, 3, 4, 5, 8, 12, oranother desired number) on one lateral side of the catheter could be influid communication with a single associated valve 90 via a commonchannel or multiple channels so that opening of the valve inflates theballoons and causes a multi-balloon and multi-increment bend in the axisof the catheter. Still further variations are possible. For example, insome embodiments, channels 52 may be formed at least in-part by flexibletubes affixed within an open or closed channel of substrate 38, or gluedalong a surface of the substrate. The tubes may comprise polymers (suchas polyimide, PET, nylon, or the like), fused silica, metal, or othermaterials, and suitable tubing materials may be commercially availablefrom Polymicro Technologies of Arizona, or from a variety of alternativesuppliers. The channels coupled to the proximal end of the actuatablebody may be assembled using stacked fluidic plates, with valves coupledto some or all of the plates. Suitable electrically actuated microvaluesare commercially available from a number of suppliers. Optionalembodiments of fluid supply systems for all balloon arrays describedherein may have all values mounted to housing 14 or some other structurecoupled to and/or proximal of) the proximal end of the elongate flexiblebody. Advantageously, accurately formed channels 52 (having sufficientlytight tolerance channel widths, depths, lengths, and/or bends or otherfeatures) may be fabricated using microfluidic techniques, and may beassembled with the substrate structure, so as to meter flow of theinflation fluid into and out of the balloons of all of the actuationarrays described herein.

A variety of known lab-on-a-chip and lab-on-a-foil production techniquescan be used to assemble and seal the substrate layers, with manyembodiments employing thermal fusion bonding, solvent bonding, welding(and particularly ultrasound welding), UV-curable adhesives, contactadhesives, nano-adhesives (including doubly cross-linked nano-adhesiveor DCNA), epoxy-containing polymers (including polyglycidylmethacrylate), plasma or other surface modifications, and/or the likebetween layers. For high fluid pressure systems, third generationnano-adhesive techniques such as CVD deposition of less than 400nanometer layers of DCNA materials may facilitate the use ofhigh-strength polymer materials such as PET. Channels of suchhigh-pressure systems may optionally be defined at least in part by PETand/or fused silica tubing (which may be supported by a substrate alongsome or all of the channel, and/or may be bundled together with otherfused silica tubing along some or all of its length ideally in anorganized array with tubing locations corresponding to the balloonlocations within the balloon array, analogous to the organization of acoherent fiber optic bundle), or the like. Any valves mounted to thesubstrate of the balloon array may be electrically actuated usingconductive traces deposited on a surface of a substrate layer prior tobonding, with an overlying layer sealing the traces in the interior ofthe substrate. Valve members may move when a potential is applied to anactuation material using the traces, with that material optionallycomprising a shape-memory alloy, piezoelectric, an electrically actuatedpolymer, or the like. Still further alternative actuation materials mayinclude phase change materials such as wax or the like, with the phasechange being induced by electrical energy or optical energy (such aslaser light transmitted via an optical fiber or printed pathway betweenlayers of the substrate). In some embodiments, the actuation materialand valve member may be formed using 3-D printing techniques. Multiplexcircuitry may be included in, deposited on a layer of, or affixed tosubstrate 38 so that the number of electrical traces extendingproximally along catheter body 12 may be less than the number of valvesthat can be actuated by those valves. The valves may take any of a widevariety of forms, and may employ (or be derived from) known valvestructures such as known electrostatically-actuated elastomericmicrofluidic valves, microfluidic polymer piston or free-floating gatevalves, layered modular polymeric microvalves, dielectric elastomeractuator valves, shape memory alloy microvalves, hydrogel microactuatorvalves, integrated high-pressure fluid manipulation valves employingparaffin, and the like. Along with electrically actuated microvalves,suitable valves may be optically actuated, fluid actuated, or the like.

It should be understood that many of the valves shown herein areschematic, and that additional or more complex valves and channelsystems may be included to control inflation and deflation of theballoons. One or more valves in the system may comprise gate valves(optionally normally closed, normally open or stable), so as to turninflation fluid flow from the fluid source to at least one balloon on oroff. Deflation may optionally be controlled by a separate gate valvebetween each balloon (or groups of balloons) and one or more deflationport of substrate 38 (the fluid from the balloon optionally exiting fromthe substrate to flow proximally between radially inner and outer sealedlayers of the catheter) or housing 14. Alternative 2-way valves mayallow i) communication between either the fluid source and the balloon(with flow from the balloon being blocked), or ii) between the balloonand the deflation outflow (with the flow from the fluid source beingblocked). Still further alternatives may be employed, including a 3 wayvalve having both of the above modes and iii) a sealed balloon mode inwhich the balloon is sealed from communication with the fluid source andfrom the deflation outflow (with flow from the source also beingclosed).

Referring now to FIG. 7, an optional catheter structure employs analternative balloon array structure having one or more elongate balloons204 that each extend axially, with balloons 204 here being formed in alayered substrate 208 so that the balloons together define a balloonarray 206 that can frictionally engage or latch against coils to helpinhibit lateral bending of a catheter body. When deflated, the loops 202of the helical coils can move away from (or if separated, toward) eachother, allowing the catheter body to flex (and straighten). In contrast,fluid expansion of balloons 208 causes each axial balloon to radiallyengage a plurality of coils 202, inhibiting movement of the coils towardor away from each other so as to add axial stiffness to the catheterbody. Interestingly, this can make it more difficult to bend a straightportion of the catheter, and/or can make it more difficult for a bentportion of the catheter to straighten (or otherwise alter its axialconfiguration). As described above, substrate 208 may be disposedbetween inner and outer coils so that the axially oriented balloonsradially engage either (or both); or the substrate may be disposedradially outward of the coil to be engaged with the edges of thesubstrate affixed together so as to limit radial displacement of theballoons and promote firm radial engagement between the expanded balloonand the coil. Still further alternatives are available, including theuse of semi-rigid or other radial support materials in the substrate,with or without edges affixed together. As can also be understood withreference to FIGS. 4C and 7, bend-inducing balloons may be combined withbend-inhibiting balloons by including both types of balloons on a singlesubstrate (optionally on opposed sides) or on separate substrates.Advantageously, the substrate, balloon, and fluid supply and controlstructures of these bend-change-inhibiting balloon arrays may includethe characteristics described above for the corresponding structures ofthe balloon articulation systems.

Referring now to FIG. 8, components of an exemplary catheterarticulation system 292 can be seen, with these components generallybeing suitable for use in catheter system 1 of FIG. 1. In thisembodiment, a catheter 294 has a distal articulated portion 296, withthe articulated portion optionally including axially separatearticulation sub-portions or segments, and alternatively having a singlerelatively continuously articulated length. An insertion sheath/inputassembly 295 is included in the system user interface, and both assembly295 and the proximal end of catheter 294 are detachably coupleable witha proximal housing 298 using flexible cables (and quick-disconnectcouplers), with the housing containing a battery, a processor, areplaceable compressed fluid cartridge, valves, and the like. Housing298 also includes or contains additional components of the userinterface, and is sized for positioning by a single hand of a user, butneed not be moved during use of catheter 294. Commands to effectautomated bending and elongation of distal portion 296 during use mayoptionally be input into the system by bending and axial insertion ofinput 297 relative to a proximal body of the introducer sheath, therebyemploying manual movements of the user which are already familiar tophysicians that employ catheter-based diagnostic and therapeutic tools.

Regarding some of the user interface components of articulation system292, use of input 297 for controlling the articulation state of catheter294 will be described in more detail hereinbelow. In addition to input297, a number of additional (or alternative) user interface componentsmay be employed. As generally indicated above, the user interface mayinclude a housing affixed to a proximal end of catheter 294, with thehousing having a joystick as described above regarding FIG. 1-1.Trackballs or touchpads may be provided in place of a joystick, and asthe catheters and other structures described herein may have more thantwo degrees of freedom, some embodiments may include two offsetjoysticks, with a more proximal joystick on the handle being used tolaterally deflect the catheter along a proximal X-Y segment and a moredistal joystick of the same handle being used to laterally deflect thecatheter along a more distal X′-Y′ segment. These two deflections may beused to enter movement commands in a manner analogous to positioning ofa robotic base using the first joystick and then articulating a wristmounted to that base with the second joystick, with the joysticksproviding either position or velocity control input to the cathetersystem. An input wheel with a surface that rolls along the axis of thehousing can be used for entering axial elongation movement commands, andthe housing may have a circumferential wheel that can be turned by thesystem user to help provide a desired alignment between an orientationof the housing relative to the lateral deflections of the catheter asseen in the remote imaging display. Still further alternative userinterface systems may employ computer workstations such as those ofknown robotic catheter or robotic surgical systems, which may includeone or more 3-D joysticks (optionally including an input allowing 4D,5D, or even more degrees of freedom), housings mimicking those ofmechanically steerable catheter systems, or the like. As seen in theembodiment of FIG. 8, still further optional components include atouchscreen (which may show a graphical representation of distalarticulated portion 296 (one or more segments of which can betouch-selected and highlighted so that they articulate in response tomovement of input 297), pushbuttons, or the like. Still furtheralternative user interface components may include voice control, gesturerecognition, stereoscopic glasses, virtual reality displays, and/or thelike.

Referring now to FIG. 9, selected components of an articulated portion302 of an articulated catheter 304 can be seen in more detail. Aplurality of inflated balloons 306 are offset from an axis 308 ofcatheter 304 along a first lateral orientation +X, so that the balloonsurge corresponding pairs of axial (proximal and distal) surfaces on theloops of coil 310 apart. This urges the coil to bend away from inflatedballoons 306 away from the +X orientation and toward the −X lateralorientation. Uninflated balloons 312 a, 312 b, and 312 c are offset inthe lateral −X, −Y, and +Y orientations, respectively, allowingselective inflations of differing subsets of these balloons to bend axis308 in differing directions. Inflation of opposed balloons (such as −Xand +X, or −Y and +Y, or both) may elongate coil 314 along axis 308.Note that a distal portion of coil 314 has been omitted from the drawingso that the arrangement of the balloons can be more clearly seen. Thisembodiment shows relatively standard offset balloon shapes, with theaxes of the balloons bent to follow the coil. In this and otherembodiments, a single balloon between coils may impose a bend in axis308 in a range from 1 to 20 degrees, more typically being in a rangefrom 2½ to 15 degrees, and often being from 6 to 13 degrees. To allow asingle inflation lumen to achieve greater bend angles, 2, 3, 4, or moreballoon inflation lumens or ports adjacent the balloons may be in fluidcommunication with a single common fluid inflation lumen.

Referring now to FIGS. 9-12, an exemplary integrated balloon array andarray substrate design and fabrication process can be understood. Asseen in FIGS. 9 and 10, a cylinder 318 is defined having a diametercorresponding to a helical coil axis 320 of coil 310, with the coil axistypically corresponding to the central axis of the coil wire (so thatthe helical axis winds around the central axis of the elongate body).Desired balloon centerlines 322 are here defined between loops of thecoil. Alternative balloon centerlines may extend along the coil axis, ascan be understood with other embodiments described below. A flat pattern324 of the balloon centerlines 322 can be unwrapped from cylinder 318,with the flat pattern optionally forming a repeating pattern extendingalong a helical wrap of the cylinder, the helical pattern unwrapoptionally being counter wound relative to coil 310 and typically havinga pitch which is greater than that of the coil. As can be understoodwith reference to FIGS. 11 and 12, the repeated flat pattern 324 can beused to define a repeating substrate pattern 326, with the substratepattern here including, for each balloon in this portion of the array, aballoon portion 328, a multi-lumen channel portion 330, and a connectorportion 332 for connecting the balloon to the multi-lumen channelportion. The connector portions and balloons here extend from a singleside of the multi-lumen channel portion; alternative embodiments mayhave connector portions and balloons extending from both lateral and/orcircumferential sides. The loops of the substrate helix may alsooverlap. In other embodiments, the flat pattern (and associatedsubstrate and multi-lumen channels) may wind in the same direction asthe coil, with the balloons and channel structures optionally extendingalong a contiguous strip, the balloons optionally having channels alongone or both axial sides of the strip and the balloons protrudingradially from the strip and between the loops of the coil so thatconnector portions 332 may optionally be omitted. Such embodiments maybenefit from a thicker and/or polymer coil. Regardless, the helicalballoon array structure may facilitate lateral bending of the catheteralong its axis and/or axial elongation of the catheter without kinkingor damaging the substrate material along the fluid flow channels, as thesubstrate loops may slide relative to each other along an inner or outersurface of coil 310 (often within a sealed annular space between innerand outer sheaths bordering the inner and outer surfaces of thecatheter).

Advantageously, the substrate pattern may then be formed in layers asgenerally described above, with at least a portion (often the majority)of each balloon being formed from sheet material in a first or balloonlayer 334 (optionally by blowing at least a portion of the balloon fromsuitable sheet material into a balloon tool) and some or all of thechannels being formed from sheet material in a second or channel layer336. The layers can be bonded together to provide sealed fluidcommunication between the balloons and the other components of the fluidsupply system, with the outline shapes of the balloon portions 328,connector portions 332, and channel portions being cut before bonding,after bonding, or partly before and partly after. Note that a portion ofthe balloon shape may be imposed on the channel layer(s) and that aplurality of channel layers may be used to facilitate fluidcommunication between a plurality of helically separated balloons(including balloons along a single lateral orientation of the assembledcatheter) and a common fluid supply channel. Similarly, a portion (oreven all) of the channel structure might alternatively be imposed on theballoon layer, so that a wide variety of architectures are possible.Formation of multiple balloons 334 and channels 330, and bonding of thelayers can be performed using parallel or batch processing (with, forexample, tooling to simultaneously blow some or all of the balloons fora helical balloon array of an articulation sub-portion, a lasermicromachining station that cuts multiple parallel channels,simultaneous deposition of adhesive materials around multiple balloonsand channels), or sequentially (with, for example, rolling toolingand/or roll-by stations for balloon blowing, laser cutting, or adhesiveapplying tooling), or a combination of both. The number of balloonsincluded in a single helical substrate pattern may vary (typically beingfrom 4 to 80, and optionally being from 4 to 32, and often being from 8to 24). The balloons may be spaced for positioning along a singlelateral catheter bending orientations, along two opposed orientations,along three orientations, along four orientations (as shown), or thelike. Channel portion 330 may terminate at (or be integrated with) aninterface with a multi-channel cable 334 that extends proximally alongthe coil (and optionally along other proximal balloon array portionsformed using similar or differing repeating balloon substrate patterns).A wide variety of alternative balloon shapes and balloon fabricationtechniques may be employed, including blowing a major balloon portionfrom a first sheet material and a minor portion from a second sheetmaterial, and bonding the sheets surrounding the blow portions togetherwith the bond axially oriented (as shown in FIG. 10) so that the sheetsand substrate layers are oriented along a cylinder bordering the coil,or with the bond radially oriented so that the sheet material adjacentthe bonds is connected to adjacent substrate by a bent connector portionor tab.

Referring now to FIGS. 12A and 12B, an alternative coaxial balloon/coilarrangement can be understood. In these embodiments, balloons 364 aremounted over a coil 366, with a plurality of the balloons typicallybeing formed from a continuous tube of material that extends along thehelical axis of the coil. The balloon material will generally have adiameter that varies locally, with the balloons being formed fromlocally larger diameter regions of the tube, and the balloons beingseparated by sealing engagement between the tube material and coiltherein at locally smaller diameters of the tube. The variation indiameter may be formed by locally blowing the balloons outward from aninitial tube diameter, by locally heat-shrinking an initial tubediameter, or both, and adhesive or heat-bonding between the tube andcoil core therein may enhance sealing. In alternative embodiments, metalrings may be crimped around the tubular balloon material to affix (andoptionally seal) the tube to the underlying helical coil. Some or evenall of the variation in diameter of the balloon material along the coilmay be imposed by the crimped rings, though selective heat shrinkingand/or blowing of the balloons and/or laser thermal bonding of theballoon to the coil may be combined with the crimps to provide thedesired balloon shape and sealing. Regardless, fluid communicationbetween the inner volume of the balloon (between the balloon wall andthe coil core) may be provided through a radial port to an associatedlumen within the coil core. As can be understood with reference to coilassembly 360 of FIG. 11A, the balloons may have outer surface shapessimilar to those described above, and may similarly be aligned along oneor more lateral bending orientations. As can be understood withreference to assemblies 360 and 362 of FIGS. 12A and 12B, bend anglesand radii of curvature of the catheter adjacent the balloon arrays maybe determined by an axial spacing (and/or number of loops) betweenballoons, and/or by selective inflation of a subset of balloons (such asby inflating every other balloon aligned along a particular lateralaxis, every third aligned balloon, every forth aligned balloon, and soon).

Referring now to FIG. 13, an exemplary catheter 430 has an articulatedportion 432 that includes a plurality of axially separate articulatedsegments or sub-portions 434 a, 434 b, 434 c, and 434 d. Generally, theplurality of articulation segments may be configured to facilitatealigning a distal end of the catheter with a target tissue 436. Suitablearticulation segments may depend on the target tissue and plannedprocedure. For example, in this embodiment the articulation segments areconfigured to accurately align a distal end of the catheter with theangle and axial location of the native valve tissue, preferably for anypatient among a selected population of patients. More specifically, thecatheter is configured for aligning the catheter axis at the distal endof the catheter with (and particularly parallel to) an axis of thetarget tissue, and (as measured along the axis of the catheter) foraxially aligning the end of the catheter with the target tissue. Suchalignment may be particularly beneficial, for example, for positioning aprosthetic cardiac valve (optionally an aortic valve, pulmonary valve,or the like, and particularly a mitral valve) with tissues of oradjacent a diseased native valve. Suitable catheter articulationcapabilities may also, in part, depend on the access path to the targettissue. For alignment with the mitral valve, the catheter may, forexample, be advanced distally into the right atrium via the superior orinferior vena cava, and may penetrate from the right atrium through theseptum 438 into the left atrium. Suitable transceptal access may beaccomplished using known catheter systems and techniques (thoughalternative septal traversing tools using the articulated structuresdescribed herein might alternatively be used). Regardless, to achievethe desired alignment with the native valve tissue, the catheter may beconfigured to, for example: 1) from distally of (or near) the septum,form a very roughly 90 degree bend (+/− a sufficient angle so as toaccommodate varying physiologies of the patients in the population); 2)extend a distance in desired range in three dimensions, including a)apically from the septal penetration site and b) away from the plane ofthe septal wall at the penetration; and 3) orient the axis of thecatheter at the distal end in three dimensions and into alignment withthe native valve tissue.

To achieve the desired alignment, catheter 430 may optionally provideconsistent multi-axis bend capabilities as well as axial elongationcapabilities, either continuously along the majority of articulatableportion 432 of catheter 430, or in articulated segments at regularintervals extending therealong. Alternative approaches may employ morefunctionally distinguished articulation segments. When present, eachsegment may optionally have between 4 and 32 balloons, subsets of theballoons within that segment optionally being oriented along from 1 to 4lateral orientations. In some embodiments, the axis bending balloonswithin at least one segment may all be aligned along a single bendorientation, and may be served by a single inflation lumen, often servedby a modulated fluid supply that directs a controlled inflation fluidvolume or pressure to the balloons of the segment to control the amountof bending in the associated orientation. Alternative single lateralbending direction segments may have multiple sets of balloons served bydifferent lumens, as described above. For example, segments 434 a and434 b may both comprise single direction bending segments, each capableof imposing up to 60 degrees of bend angle and with the former having afirst, relatively large bend radius in the illustrated configuration dueto every-other axial balloon being inflated, or due to inflation with alimited quantity of inflation fluid. In segment 434 b, all but thedistal-most four balloons may be inflated, resulting in a smaller bendradius positioned adjacent segment 434 a, with a relatively straightsection of the catheter distal of the bend. Segment 434 c may haveballoons with four different bend orientations at a relatively highaxial density, here having selected transverse balloons (such as 6+Xballoons and 2−Y balloons) inflated so as to urge the catheter to assumea shape with a first bend component away from the septal plane and asecond bend component laterally away from the plane of the bends ofsegments 434 a and 434 b. Segment 434 d may comprise an axial elongationsegment, with opposed balloons in fluid communication with the one ormore inflation fluid supply lumen of this segment. Axial positioning ofthe end of the catheter may thus be accurately controlled (within therange of motion of the segment) by appropriate transmission of inflationfluid. Advantageously, such specialized segments may limit the number offluid channels (and the cost, complexity and/or size of the catheter)needed to achieve a desired number of degrees of freedom and a desiredspatial resolution. It should be understood that alternative segmentarrangements might be employed for delivery of a prosthetic heart valveor the like, including the use of three segments. The valve might bepositioned using a three-segment system by, for example, inserting thecatheter so that the septum is positioned along the middle of the threesegments, ideally with the catheter traversing the septum at or near themiddle of the middle segment.

Referring now to FIG. 14, a perspective view of an exemplary introducersheath/input assembly for use in the systems of FIGS. 1 and 8 can beseen in more detail. Introducer/input assembly 460 generally includes anintroducer sheath assembly 462 and an input assembly 464. Introducer 462includes an elongate introducer sheath 466 having a proximal end 468 anda distal end 470 with an axial lumen extending therebetween. A proximalhousing 472 of introducer 462 contains an introducer hemostasis valve.Input 464 includes a flexible joystick shaft 474 having a distal endslidably extending into the lumen of introducer housing 472, and aproximal end affixed to an input housing 476 containing an input valve.A lumen extends axially through input 464, and an articulatable catheter480 can be advanced through both lumens of assembly 460. A cable orother data communication structure of assembly 460 transmits movementcommands from the assembly to a processor of the catheter system so asto induce articulation of the catheter within the patient. Morespecifically, when the catheter system is in a driven articulation mode,and a clutch input 482 of introducer/input assembly 460 is actuated,movement of input housing 476 relative to sheath housing 472 inducesarticulation of one or more articulatable segment of catheter 480 nearthe distal end of the catheter, with the catheter preferably having anyone or more of the articulation structures described herein. The valveswithin the housings of introducer/input assembly may be actuatedindependently to axially affix catheter 480 to introducer 462, and/or toinput 464.

Referring now to FIGS. 1, 8, 14-16J, and Table 1, introducer/inputassembly 460 can be used during operation of the catheter system inmultiple different modes. Table 1 summarizes exemplary systemconfiguration and operation of some exemplary modes, and FIG. 15schematically illustrates components of introducer assembly 462 that canbe used to help implement those modes. FIGS. 16 and 16A schematicallyillustrate manual movement of system components during manualmanipulation of the catheter, in an exemplary manual mode. FIGS. 16B-16Eschematically illustrate exemplary 3-D movement input commands andassociated automated changes in articulation state of the articulatedcatheter. FIGS. 16F-16H schematically illustrate a combination ofmeasured manual movement of the catheter body through the introducer andautomated changes in articulation state of the articulation catheter inan exemplary follow-a-curve mode, and can also help to understand anexemplary axial elongation recovery mode. FIGS. 16I and 16Jschematically illustrate measured manual axial movement and locallyvarying a stiffness of the catheter so as to tailortrackability/pushability of the overall catheter.

TABLE 1 3-D Powered Position/ Manual Follow a Orientation OperationCurved Path Movement Introducer Open Open* Fixed Valve Input Valve OpenFixed* Open Introducer/Input Fixed Open Open Interface Comments Manualinsertion Combines Proximal and rotation measured catheter adjacentmanual axial body is introducer movement and stationary analogous topowered lateral relative to standard catheter deflection. insertionmanipulation. Path may sheath and May use be predefined, surroundingwith a set sensed tissue, distal from guidewire or analogous todeflection, lumen, or a soft- and/or with set defined by tissue-mountedlocally catheter robotic adjusted shape state. manipulator catheter Maystart base. stiffness. with axial elongation recovery.

Referring now to FIGS. 15 and 16, introducer/input assembly 460 can beused in a manual mode by affixing the introducer housing 472 to theinput housing 476, and by opening the valves of both so that catheter480 can rotate and slide axially through the coaxial lumens ofintroducer 462 and input 464. The housings can be affixed together usinga releasable input/introducer interface 484, with exemplary interfacescomprising corresponding threads, a Luer lock, or the like. Flexiblejoystick 474 may extend into or through introducer housing 472, with thejoystick being rotatable about the lumen and axially slidable within arange of movement limited by the interface 484 and slide limiting stops486. Note that the flexible joystick may optionally slide within a rigiddistal extension of introducer housing 472, allowing the system user tograsp the extension outside the patient to help inhibit movement orbending of the sheath 466 within the access site. Alternatively, theflexible joystick may be extendable distally within the flexible sheathtoward or even into the patient.

The valves may comprise elastomeric valve bodies such as O-rings or thelike which are axially compressed when closed (so that they are pushedradially inward into axial restraining engagement with the outer surfaceof the catheter) and axially released when opened (so as to or allowaxial sliding of the catheter body therethrough). Hence, the valvehousings may comprise threads, Luer locks, hemostat-like lockable pinchhandles, or the like, and may alternatively comprise fluid inflatable orelectrically powered valve actuators. When open, sliding engagementbetween the valve bodies and the catheter may help maintain hemostasis,and that an additional hemostatis structure (such as a duck bill valvebody, a slit foam valve body, or the like) may be included along one orboth lumens and/or between the flexible joystick and the surroundingintroducer housing to promote hemostasis around smaller diameterguidewires, prior to insertion of the catheter, when the valves are indifferent configurations, etc.

As the catheter system mode and drive signals sent to inflation fluiddrives or other actuation components may vary in correlation with theconfigurations of the introducer valve, input valve, and interface,sensors 488 may be associated with any one or more of these, with thesesensors transmitting signals corresponding to the configuration of theassociated structure and facilitating use of their manualreconfiguration as an input to the system processor to alter the mode ofthe catheter system. Regardless, in the exemplary embodiment, aplurality of sensors are used to sense movements of catheter systemcomponents of or adjacent the introducer/input assembly 460, and totransmit movement command inputs in response. For example, an axialmovement command sensor 490 can be mounted to the introducer 462, input464, and/or catheter 480 and can transmit signals corresponding to anaxial displacement or movement of the input (and/or catheter) relativeto the introducer. Exemplary axial sensors may comprise electricalcoils, hall effect sensors, optical sensors (optionally similar to thoseof an optical computer mouse), or the like, and will preferably measureaxial displacement of the input housing relative to the introducerhousing, so that the introducer housing operates as an input base. Alateral movement command sensor 492 similarly measures lateral and/orangular displacement relative to the lumenal axis of the introducerhousing. Lateral sensor 492 may be mounted to the flexible joystick,input housing, and/or catheter 480, and optionally comprises an opticalFiber Bragg Grating flex sensor or flex circuit flex sensor extendingalong the flexible shaft of the flexible joystick 474. Lateral sensor492 may hence comprise relatively simple cost-effective optical fibersor other components that send optical or electrical signals to beprocessed using re-usable processing structures, allowing theintroducer/input assembly to be single-use items and avoiding thedangers of sterilization and re-use. Lastly, a clutch input 494 maycomprise a simple switch, ideally a normally off switch which operatesto inhibit automated articulation in response to movement of the inputstructures unless a button is held down or the like.

Referring now to FIGS. 16 and 16A, operation of the catheter system inthe manual mode is suitable for rapid manual movements through easilynavigated portions of the lumen, and may provide tactile feedback to thesystem operator. Axial insertion 502 and rotation 504 of catheter 480near the introducer sheath, and can effect corresponding axial androtational movements 506, 508 of a distal end 500 of the catheter.However, where the catheter extends along a tortuous 3-D path 510 asshown schematically in FIG. 16A, there may be significant differencesbetween the manual input movements and those exhibited by the distal endof the catheter. Note that this manual mode can be performed withoutmany of the components of introducer/input assembly 460, for example,using a simple introducer prior to attachment of the input assembly orthe like. Note also that the orientations of the input movements 502,504 and output movements 506, 508 may be quite different, particularlywhen the output movements are viewed on a display that is offset fromthe patient. While physicians skilled with catheters and guidewires canreadily handle these differences, there can be advantages to increasingthe orientational alignment, particularly by rotationally aligning (orallowing the system user to provide a desired rotational alignment)between the X-Y input orientations and the X′-Y′ output orientationalignments. Though complex paths are omitted from the illustratedautomated articulation modes that follow, the exemplary systems andmethods help provide such input-output rotational alignment.

Referring now to FIGS. 15 and 16B, the catheter system may be used in anautomated 3-D mode by closing the introducer valve (so that catheter 480is held in a stationary axial and rotational position by the valve ofthe introducer). The valve of the input is opened and the interfacebetween the introducer and input is separated so that the input can bemoved relative to the introducer within the range of axial motion of theflexible joystick 474 and the lateral flexibility of the joystick andthe catheter shaft extending therethrough. Movement command signals arenot effective prior to actuation of the clutch, so that the system usercan position the input relative to the introducer at a desirable initialrelative position and orientation. Input housing 476 may, for example,be rotatable about the axis of the lumen therethrough relative to theintroducer sheath housing 472. Where the lateral displacement sensorcomprises a flex sensor affixed to the flexible joystick, rotation ofthe input can be used to orient the X-Y lateral deflections 512 inalignment with the displayed images of output movements, optionallyusing one or more small test lateral input movement commands.Regardless, while the clutch input is depressed, lateral input 512causes joystick 474 to flex and transmit associated sensor signals to aprocessor of the system. The processor determines appropriate drivesignals to send to an appropriate balloon inflation valve (or otheractuation system components) so that distal end 500 is urged toward alateral deflection output movement 514, the results of which areillustrated in FIG. 16B. Note that flexing of the shaft in a transverselateral direction would result in the distal end being urged tosimilarly move in a transverse lateral direction, thereby providing X-Ydeflection input and output. Note also that the output movement maycorrespond in magnitude to the input command movement, but will oftendiffer in size. For example, output displacement distances may beproportional to but smaller than input displacements; inputs and outputsmay have similar orientations but may not have a constantproporationality; output displacement angles may be smaller than, thesame as, or larger than input flex angles; and/or the like.

Referring now to FIGS. 16C and 16D, along with (or instead of) X-Ylateral deflection, introducer/input assembly may be used to acceptaxial (Z) input movement commands, with the assembly accommodatingsimultaneously in the exemplary 3-D mode. While the clutch input isdepressed, input housing 476 may be moved toward introducer housing 472so as to provide an axial input movement command 516. Flexible joystick474 slides into introducer housing 472, and the axial sensor sendscorresponding axial command signals to the process that result in anaxial output movement 518. Note that some systems may helporientationally align these axial inputs and outputs. For example, anorientation of a display image may be rotated using image processing tohelp align displayed axial movements of distal end 500 with the input;and/or a flexibility of the sheath between the introducer housing andthe patient may allow the system user to help align the axial inputswith the associated displayed axial movements. Many other systems mayrely on the system user to accommodate axial input/output orientationaldisparity. In the exemplary embodiment illustrated, axial alignment isnot provided (so that Z′ may differ from Z), but if an initial testinput command indicates the input and outputs lack a desired rotationalalignment, the user may simply rotate input housing 476 relative tointroducer housing 472. Re-testing and refining of rotational alignment(if desired) should provide the desired lateral (X-Y) alignment quickly,which will help the user to maintain accurate control despite the lackof axial alignment. Other systems may have a rotational input or knobthat provides an electronic signal to achieve a similar lateralorientational alignment based on user input.

As can be understood with reference to FIGS. 16D and 16E, overall inputmovement commands may be received (and implemented) by the cathetersystem as a series of partial movements. To initiate the beginning of afirst movement command, the user can actuate the clutch by pressing aclutch button or the like. The processor may store a configuration ofthe input when the clutch is actuated, and may derive drive signals toseek to perform the commanded movement relative to that initialconfiguration. When the input approaches an end of its range of motion(which may be imposed by the input device, the anatomy of the patient,the comfort of the physician, or the like) prior to achieving a desiredconfiguration of the catheter, the system user may release the clutch.The system processor may then maintain the articulated portion of thecatheter in the configuration or state it was in when the clutch wasreleased, and the system user can return the input (without actuatingthe clutch button) back toward a middle of a range of motion of theinput. The clutch button can then be actuated to again input a portionof the desired overall movement command 512′; the system may in responseinitiate the remainder of (or another portion of) the desired movement514′. This can be analogous to lifting up a computer mouse from the edgeof the desk prior to getting a cursor to the desired position, moving itback toward the middle of the desk, and putting it back down to allowcontinued cursor movement.

Referring now to FIGS. 16F and 16G, to initiate a movement of a distalend 500 in an exemplary follow-a-curve mode, catheter 480 can be axiallyaffixed to input housing 476 by closing the input valve, and may allowedto slide relative to introducer housing 472 by opening the introducervalve, with the interface between the valves being detached. A goal ofthis movement may be (for example) for the catheter tip and body to atleast approximately follow a curving 3-D path 520, with the path havinga first curved path segment 520 a that differs in radius of curvatureand/or orientation of curvature from that of a second path segment 520b, both of which may differ from those of another path segment 520 c,and so on. To accommodate the desired movement, the articulated portionof the catheter may have a distal-most first articulated segment 522 aand a second articulated segment 522 b, and may also have a thirdarticulated segment 522 c, and optionally one or more additionalarticulated segments, with these segments typically being axiallycoupled and independently articulable.

Curve 520 may be defined in a number of different ways. Optionally,curve 520 may be determined prior to initiating a particular axialmovement, such as by determining a desired path through a 3-D surfacemodel of the body lumen or volume (such as a blood/tissue boundary alonga chamber of the heart). Curve 520 might also be defined by a structure,such as by a guidewire over which catheter 480 is to be advanced. Insome embodiments, curve 520 may be generated while the catheter isadvancing, such as by using flexible joystick 474 to input a lateralposition or curvature of the path associated with the concurrent axialjoystick configuration. In many embodiments, segments proximal of thedistal most first segment 522 a may be driven from their currentconfiguration toward a configuration (actual or commanded or acombination of both) of the distally adjacent segment. Note that in someembodiments, the axial locations of the segments along the elongate bodymay change or overlap. Regardless, while some embodiments of cathetersystems used to implement some or all of the modes described herein mayinclude articulation portions extending proximally from a distal end ofthe distal-most articulated segment all the way to the access site, manyembodiments will rely on passive (un-articulated) proximal portions thatextend proximally from the articulated portion and/or segments withinthe patient body, and that such a passive proximal portion will often bebent laterally along the curving path proximal of the articulatedportion. Manual insertion of catheter 480 can be used to provide distaladvancement of both the articulated portion and any passive proximalportion along curving path 420 by sensing the manual axial displacementof the catheter via the axial sensor of introducer/input assembly 460,and by driving the articulated segments of the catheter (one or more of522a, 522 b, 522 c . . . ), toward a curvature configurationcorresponding to that of an adjacent path segment (one or more of 520a,520 b, 520 c).

Referring to FIGS. 16F and 16G, the lateral driving of the articulatedsegments may occur during axial movement, and/or between incrementalaxial movements. One or more of the articulated segments may be drivenso as to assume a curvature associated with an approaching segmentbefore the catheter segment and curve segment are aligned, or once theyare aligned. Nonetheless, lateral articulation may be initiated bydepressing the clutch of the input and manually moving the input housing476 relative to the introducer housing 472. Once the input is at or nearthe end of its range of motion (as seen in FIG. 16G), the clutch can bereleased. As the valves configurations may be reversed to allow theinput to be retracted proximally without moving catheter 480, it may beadvantageous to couple clutch release to powered valve actuators forthis mode. Regardless, as seen in FIGS. 16G and 16H, input housing 476can be withdrawn and a new axial displacement increment initiated (withcorresponding lateral deflection of articulation segments 522 a, 522 b,etc.) so that the distal end of the catheter substantially follows alongpath 520. Note that if any motion in this mode is initiated (bydepressing the clutch input, for example) the system processor maydetermine if any articulation segment of the catheter is in a partiallyor fully elongated configuration. If one or more of the segments iselongated beyond a desired configuration, and if the catheter is atleast initially advanced distally, the processor may transmit axialdrive signals so that the elongated segment(s) are retracted axiallyback to the desired length configuration in correlation with the manualdistal movement so as to have the catheter ready for a future drivenelongation movement. Once the elongate lengths of the segments are intheir desired states, such elongation recovery can be terminated.

Referring now to FIGS. 16I and 16J, yet another mode of movement withthe catheter systems described herein may employ partial inflation ofarticulation balloons so as to locally decrease a lateral stiffness ofthe catheter so as to tailor a pushability and/or trackability of thecatheter for a particular body lumen, and ideally for the axialrelationship of the catheter relative to bends of the lumen.Trackability, pushability, torqueability, and crossability of are knowncharacteristics of catheters which may be quantitatively determinedsubjectively (by asking a number of users to rate the catheters for oneor more of these characteristics), empirically (by measuring movementinputs and outputs in a controlled test), and/or analytically (bymodelling interaction of the catheter and resulting catheter performancebased on characteristics or properties of the catheter structure).Pushability generally reflects the ability of a distal end of thecatheter to advance distally within a bending lumen in response to anaxial insertion performed from proximally of the lumen, whiletrackability generally reflects the ability of the distal end of thecatheter to follow a path through a bending lumen (optionally as definedby a guidewire or the luminal wall) in response to axial insertion. Bothpushability and trackability can vary with a number of differentcharacteristics of the catheter structure (both often improving withincreased outer lubricity, for example), but in at least somecircumstances they may contradict each other. For example, pushabilitymay be enhanced by increasing an axial stiffness of at least an axialsegment of a catheter, while trackability may be enhanced by decreasingthat axial stiffness. The fluid articulated catheters described hereinmay help overcome this challenge for a particular body lumen, becausethe axial stiffness of the catheter segments can be independently variedby varying balloon pressure, optionally without applying pressure so asto impose lateral bends in any particular direction (absentenvironmental forces against the catheter).

In FIGS. 16I and 16J, a body lumen has a first bend B1 and a second bendB2 with a straight section between the bends. Good overall pushabilityand trackability of the catheter in the position of FIG. 16I may benefitfrom a catheter structure with high lateral flexibility (low stiffness)along catheter segment 520 b (proximal of and along bend B1), and arelatively high stiffness (low flexibility) along catheter segments 520a and 520 c (extending along straight lumen segments. As the catheteradvances distally so that the distal end nears bend B2, trackability maybenefit from increasing the flexibility of segment 520 a, whilepushability and trackability may overall benefit by decreasing thestiffness of segment 520 c (as it approaches or reaches bend B1), andincreasing the stiffness of segment 520 b (as it leaves bend B2 and/orextends along the straight section. By identifying highly curved andstraighter segments of the path, by measuring axial insertion of thecatheter, and adjusting a pressure of balloons of the segments, forexample, so that catheter segments approaching or along greatercurvature are less stiff (often by partial balloon inflation), and sothat catheter segments approaching or along straighter path portions aremore stiff (such as by compete deflation or inflation of the balloons ofthose segments).

Referring now to FIG. 17, two different anchor modes of catheter 480 canbe understood. In this embodiment, it is desired to align distal end 500of catheter 480 with a target tissue TT that is accessed via a branchingbody lumen BBL. To access the target tissue and/or to produce thedesired alignment, catheter 480 may advance over a guidewire GW, or maybe self-guiding, and will use lateral deflection and axial elongation ofa distal articulable catheter segment 520 a as generally describedabove. The system user has here determined it would be desirable toanchor the catheter 480 proximally of segment 520 a, for example, sothat the distal segment of the catheter will move with physiologicalmovement near the target tissue TT, so that the distal segment of thecatheter is isolated from movement proximal of the anchor location, tostabilize segment 520 a during articulation, or the like. To provide adesired anchoring engagement between an outer surface of catheter 480and the luminal wall at a first anchoring location 530 extending along arelatively straight section of the branching body lumen BBL, catheterarticulation segment 520 c may be driven so as to impose at least onebend and preferably so as to impose opposed bends, sinusoidal bends, ahelical bend, or the like. Anchoring engagement at a bent location 532of the body lumen can be provided by driving articulation segment 520 btoward a catheter bend configuration having a bend angle which isgreater than that of the body lumen bend. Note that FIG. 17 alsoillustrates lateral deflection of a flexible tip 534 of catheter 480 asimposed by guidewire GW, the lumen wall, or both. Such a flexible tiphaving a flex sensor (optionally an optical fiber or flex circuit) canmeasure such deflection and generate signals that may be used as adistal path curve sensor, as can be understood above.

Referring now to FIG. 18, a simplified manifold schematic shows fluidsupply and control components of an alternative manifold 602. Asgenerally described above, manifold 602 has a plurality of modularmanifold units or valve assembly plates 604 i, 604 ii, . . . stacked inan array. The stack of valve plates are sandwiched between a front endcap 606 and a back end-cap 608, and during use the proximal portion ofthe multi-lumen conduit core(s) extend through apertures in the frontcap and valve plates so that the proximal end of the core is adjacent toor in the back cap, with the apertures defining a multi-lumen corereceptacle. The number of manifold units or modules in the stack issufficient to include a plate module for each lumen of each of themulti-lumen core(s). For example, where an articulatable structure has 3multi-lumen core shafts and each shaft has 6 lumens, the manifoldassembly may include a stack of 6 plates. Each plate optionally includesan inflation valve and a deflation valve to control pressure in one ofthe lumens (and the balloons that are in communication with that lumen)for each multi-lumen shaft. In our 3-multi-lumen shaft/6 lumen eachexample, each plate may include 3 inflation valves (one for a particularlumen of each shaft) and 3 deflation valves (one for that same lumen ofeach shaft). As can be understood with reference to the multi-lumenshaft shown in receptacle 1 of FIG. 18, the spacing between the portsalong the shaft corresponds to the spacing between the fluid channelsalong the receptacle. By inserting the core shaft fully into themulti-lumen shaft receptacle, the plate channel locations can beregistered axially with the core, and with the ports that were drilledradially from the outer surface of the multi-lumen core. The processorcan map the axial locations of the valves along the receptacle with theaxial locations of the ports along the core shafts, so that a port intoa particular lumen of the core can be registered and associated with afluid channel of specific inflation and deflation valves. One or moreinflation headers can be defined by passages axially through thevalve-unit plates; a similar deflation header (not shown) can also beprovided to monitor pressure and quantity of fluid released from thelumen system of the articulated device. O-rings can be provided adjacentthe interface between the plates surrounding the headers andreceptacles. Pressure sensors (not shown) can monitor pressure at theinterface between each plate and the multi-lumen receptacle. It shouldbe noted that a wide variety of alternative manifold and cathetercoupler structures might also be used, including manifold systems inwhich a stacked plate connector system is used for interfacing with thecatheter, and in which an array of ports extend laterally from theconnector to provide a quick-disconnect interface with a reusable valveassembly (as shown in FIGS. 29-30C and described below).

Along with monitoring and controlling inflation and deflation of all theballoons, manifold 602 can also include a vacuum monitor system 610 toverify that no inflation fluid is leaking from the articulated systemwithin the patient body. A simple vacuum pump (such as a syringe pumpwith a latch or the like) can apply a vacuum to an internal volume orchamber of the articulated body surrounding the balloon array.Alternative vacuum sources might include a standard operating roomvacuum supply or more sophisticated powered vacuum pumps. Regardless, ifthe seal of the vacuum chamber degrades the pressure in the chamber ofthe articulated structure will increase. In response to a signal from apressure sensor coupled to the chamber, a shut-off valve canautomatically halt the flow of gas from the canister, close all ballooninflation valves, and/or open all balloon deflation valves. Such avacuum system may provide worthwhile safety advantages when thearticulated structure is to be used within a patient body and theballoons are to be inflated with a fluid that may initially take theform of a liquid but may vaporize to a gas. A lumen of a multi-lumencore shaft may be used to couple a pressure sensor of the manifold to avacuum chamber of the articulated structure via a port of the proximalinterface and an associated channel of the manifold assembly, with thevacuum lumen optionally comprising a central lumen of the multi-lumenshaft and the vacuum port being on or near the proximal end of themulti-lumen shaft.

Many of the flexible articulated devices described above rely oninflation of one or more balloons to articulate a structure from a firstresting state to a second state in which a skeleton of the flexiblestructure is resiliently stressed. By deflating the balloons, theskeleton can urge the flexible structure back toward the originalresting state. This simple system may have advantages for manyapplications. Nonetheless, there may be advantages to alternativesystems in which a first actuator or set of actuators urges a flexiblestructure from a first state (for example, a straight configuration) toa second state (for example, a bent or elongate configuration), and inwhich a second actuator or set of actuators are mounted in opposition tothe first set such that the second can actively and controllably urgethe flexible structure from the second state back to the first state.Toward that end, exemplary systems described below often use a first setof balloons to locally axially elongate a structural skeleton, and asecond set of balloons mounted to the skeleton to locally axiallycontract the structural skeleton. Note that the skeletons of suchopposed balloon systems may have very little lateral or axial stiffness(within their range of motion) when no balloons are inflated.

Referring now to FIG. 19, a simplified exemplary C-channel structuralskeleton 680 includes an axial series of C-channel members or frames682, 684 extending between a proximal end (toward the bottom of thepage) and a distal end (toward the top of the page) of the skeleton,with each rigid C-channel including an axial wall, a proximal flange,and a distal flange 642. The opposed major surfaces of the walls areoriented laterally, and the opposed major surfaces of the flanges areoriented axially (and more specifically distally and proximally,respectively. The C-channels alternate in orientation so that the framesare interlocked by the flanges. Hence, axially adjacent frames overlap,with the proximal and distal surfaces of two adjacent frames defining anoverlap offset. The flanges also define additional offsets, with theseoffsets being measured between flanges of adjacent similarly orientedframes.

Balloons are disposed in the channels of each C-frame 682, 684 (onlysome of which are shown). Although the balloons themselves may (or maynot) be structurally similar, the balloons are of two differentfunctional types: extension balloons 660 and contraction balloons 662.Both types of balloons are disposed axially between a proximallyoriented surface of a flange that is just distal of the balloon, and adistally oriented surface of a flange that is just proximal of theballoon. However, contraction balloons 662 are also sandwiched laterallybetween a first wall of a first adjacent C-channel 682 and a second wallof a second adjacent channel 684. In contrast, extension balloons 660have only a single wall on one lateral side; the opposite sides ofextension balloons 660 are not covered by the frame (though they willtypically be disposed within a flexible sheath or other components ofthe overall catheter system). When extension balloons 660 are fullyinflated, they push the adjacent flange surfaces apart so as to increasethe axial separation between the associated frames. Contraction balloons662 are disposed in a C-channel with an extension balloon, and as thesize of the channel will not significantly increase, the contractionballoons will often be allowed to deflate at least somewhat withexpansion of the extension balloons. Hence, offsets between adjacentsimilar frames (682, 682) will be urged to expand, and contractionoffsets between differently oriented frames (682, 684) will be allowedto decrease. In contrast, when skeleton 680 is to be driven toward anaxially contracted configuration, the contraction balloons 662 areinflated, thereby pushing the flanges of the overlapping frames axiallyapart to force the contraction overlap to increase and axially pull thelocal skeleton structure into a shorter configuration. To allow thecontraction balloons 662 to expand within a particular C-channel, theexpansion balloons 660 can be allowed to deflate. A number ofalternative frame arrangements having opposed extension/contractionballoons can also be provided, as can be understood with reference toProvisional U.S. Application No. 62/296,409 filed Feb. 17, 2016,entitled “Local Contraction of Flexible Bodies using Balloon Expansionfor Extension-Contraction Catheter Articulation and Other Uses ”(Attorney Docket No. 097805-000300US-0970626).

Note that whichever extension/contraction skeleton configuration isselected, the axial change in length of the skeleton that is inducedwhen a particular subset of balloons are inflated and deflated willoften be local, optionally both axially local (for example, so as tochange a length along a desired articulated segment without changinglengths of other axial segments) and—where the frames extend laterallyand/or circumferentially—laterally local (for example, so as to impose alateral bend by extending one lateral side of the skeleton withoutchanging an axial length of the other lateral side of the skeleton).Note also that use of the balloons in opposition will often involvecoordinated inflating and deflating of opposed balloons to provide amaximum change in length of the skeleton. There are significantadvantages to this arrangement, however, in that the ability toindependently control the pressure on the balloons positioned on eitherside of a flange (so as to constrain an axial position of that flange)allows the shape and the position or pose of the skeleton to bemodulated. If both balloons are inflated evenly at with relatively lowpressures (for example, at less than 10% of full inflation pressures),the flange may be urged to a middle position between the balloons, butcan move resiliently with light environmental forces by compressing thegas in the balloons, mimicking a low-spring force system. If bothballoons are evenly inflated but with higher pressures, the skeleton mayhave the same nominal or resting pose, but may then resist deformationfrom that nominal pose with a greater stiffness.

Referring again to FIG. 19, a C-frame skeleton 680 has two differentgenerally C-frames or members: a C-frame 682, and a bumper C-frame 684.C-frame 682 and bumper frame 684 both have channels defined by walls 644and flanges 648 with an axial width to accommodate two balloonassemblies. Bumper frame 684 also has a protrusion or nub that extendsfrom one flange axially into the channel. The adjacent axial surfaces ofthese different frame shapes engage each other at the nub, allowing theframes to pivot relative to each other and facilitating axial bending ofthe overall skeleton, particularly when using helical frame members.

Referring now to FIGS. 19 and 20, a relationship between the schematicextension/retraction frame illustration of FIG. 19 and a first exemplarythree dimensional skeleton geometry can be understood. To form anaxisymmetric ring-frame skeleton structure 690 from the schematicmodified C-frame skeleton 680 of FIG. 19, the geometry of frame members682, 684 can be rotated about an axis 688, resulting in annular or ringframes 692, 694. These ring frames retain the wall and flange geometrydescribed above, but now with annular wall and flanges beinginterlocked. The annular C-frames 682, 684 were facing differentdirections in schematic skeleton 680, so that outer C-frame ring 692 hasan outer wall (sometimes being referred to as outer ring frame 692) anda channel that opens radially inwardly, while bumper C-frame ring 694has a channel that is open radially outwardly and an inner wall (so thatthis frame is sometimes referred to as the inner ring frame 694). Ringnub 696 remains on inner ring frame 694, but could alternatively beformed on the adjacent surface of the outer ring frame (or usingcorresponding features on both). Note that nub 696 may add more valuewhere the frame deforms with bending (for example, the frame deformationwith articulation of the helical frame structures described below) asthe deformation may involve twisting that causes differential angels ofthe adjacent flange faces. Hence, a non-deforming ring frame structuremight optionally omit the nub in some implementations.

Referring now to FIGS. 21-23, uniform axial extension and contraction ofa segment of ring-frame skeleton 690 is performed largely as describedabove. To push uniformly about the axis of the ring frames, threeballoons are distributed evenly about the axis between the flanges (withcenters separated by 120 degrees). The balloons are shown here asspheres for simplicity, and are again separated into extension balloons660 and contraction balloons 662. In the straight extended configurationof FIG. 21, the extension balloons 660 of the segment are all fullyinflated, while the contraction balloons 662 are all fully deflated. Inan intermediate length configuration shown in FIG. 22, both sets ofballoons 660, 662 are in an intermediate inflation configuration. In theshort configuration of FIG. 23, contraction balloons 662 are all fullyinflated, while extension balloons 660 are deflated. Note that the stateof the balloons remains asymmetrical, so that the lengths on all lateralsides of the ring frame skeleton 690 remain consistent and the axis ofthe skeleton remains straight. Lateral bending or deflection of the axisof ring-frame skeleton 690 can be accomplished by differential lateralinflation of subsets of the extension and contraction balloons. Morespecifically, there are three balloons distributed about the axisbetween each pair of articulated flanges, so that the extension balloons660 are divided into three sets. Similarly, there are three sets ofcontraction balloons. The balloons of each set are aligned along thesame lateral orientation from the axis. Each axially aligned set ofextension balloons along a particular segment can be coupled to anassociated inflation fluid channel, and each axially aligned set ofcontraction balloons can be coupled to an associated inflation channelso that there are a total of 6 lumens or channels per segment (providingthree degrees of freedom and three orientation-related stiffnesses).Other segments may have separate fluid channels to provide separatedegrees of freedom, and alternative segments may have fewer than 6 fluidchannels. Regardless, by selectively deflating the extension balloons ofa first lateral orientation and inflating the opposed contractionballoons, a first side of ring frame skeleton 690 can be shortened. Byselectively inflating the extension balloons of the other orientationsand by selectively deflating the contraction balloons of those otherorientations, the laterally opposed portion of ring frame skeleton 690can be locally extended, causing the axis of the skeleton to bend. Bymodulating the amount of elongation and contraction distributed aboutthe three opposed extension/contraction balloon orientations, theskeleton pose can be smoothly and continuously moved and controlled inthree degrees of freedom.

While it is possible to include balloons between all the separatedflanges so as to maximize available extension forces and the like, theremay be advantages to foregoing kinematically redundant balloons in thesystem for compactness, simplicity, and cost. Toward that end, ringframe skeletons having 1-for-1 opposed extension and contractionballoons can provide the same degrees of freedom and range of motion asprovided by the segments of FIGS. 19-23 (including two transverse X-Ylateral bending degrees of freedom and an axial Z degree of freedom),and can also control stiffness, optionally differentially modulatingstiffness of the skeleton in different orientations in 3D space. Thetotal degrees of freedom of such a segment may appropriately bereferenced as being 4-D (X,Y,Z,&S for Stiffness), with the stiffnessdegree of freedom optionally having 3 orientational components (so as toprovide as many as 5-D or 6-D. Regardless, the 6 fluid channels may beused to control 4 degrees of freedom of the segment.

As can be understood with reference to FIGS. 23A-23H, elongate flexiblebodies having ring-frame skeletons 690′ with larger numbers of inner andouter ring frames 692, 694 (along with associated larger numbers ofextension and retraction balloons) will often provide a greater range ofmotion than those having fewer ring frames. The elongation or Z axisrange of motion that can be provided by balloon articulation array maybe expressed as a percentage of the overall length of the structure,with larger percentage elongations providing greater ranges of motion.The local changes in axial length that a balloon array may be able toproduce along a segment having ring frames 690, 690′ (or more generallyhaving the extension contraction skeleton systems described herein) maybe in a range of from about 1 percent to about 45 percent, typicallybeing from about 2½ percent to about 25 percent, more typically beingfrom about 5 percent to about 20 percent, and in many cases being fromabout 7½ percent to about 17½ percent of the overall length of theskeleton. Hence, the longer axial segment length of ring frame skeleton690′ will provide a greater axial range of motion between a contractedconfiguration (as shown in FIG. 23C) and an extended configuration (asshown in FIG. 23A), while still allowing control throughout a range ofintermediate axial length states (as shown in FIG. 23B).

As can be understood with reference to FIG. 23F, setting the balloonpressures so as to axially contract one side of a ring frame skeleton690′ (having a relatively larger number of ring frames) and axiallyextend the other side laterally bends or deflects the axis of theskeleton through a considerable angle (as compared to a ring frameskeleton having fewer ring frames), with each frame/frame interfacetypically between 1 and 15 degrees of axial bend angle, more typicallybeing from about 2 to about 12 degrees, and often being from about 3 toabout 8 degrees. A catheter or other articulated elongate flexible bodyhaving a ring frame skeleton may be bent with a radius of curvature (asmeasured at the axis of the body) of between 2 and 20 times an outerdiameter of the skeleton, more typically being from about 2.25 to about15 times, and most often being from about 2.4 to about 8 times. Whilemore extension and contraction balloons 660, 662 are used to providethis range of motion, the extension and contraction balloon subsets maystill each be supplied by a single common fluid supply lumen. Forexample, 6 fluid supply channels may each be used to inflate and deflate16 balloons in the embodiment shown, with the balloons on a single lumenbeing extension balloons aligned along one lateral orientation.

As can be understood with reference to ring frame skeleton 690′ in thestraight configuration of FIG. 23A, in the continuously bentconfiguration of FIG. 23F, and in the combined straight and bentconfiguration of FIGS. 23D & 23E, exemplary embodiments of the elongateskeleton 690′ and actuation array balloon structures described hereinmay be functionally separated into a plurality of axial segments 690 i,690 ii. Note that many or most of the skeleton components (includingframe members or axial series of frame members, and the like) andactuation array components (including the substrate and/or core, some orall of the fluid channels, the balloon outer tube or sheath material,and the like), along with many of the other structures of the elongateflexible body (such as the inner and outer sheaths, electricalconductors and/or optical conduits for diagnostic, therapeutic, sensing,navigation, valve control, and other functions) may extend continuouslyalong two or more axial segments with few or no differences betweenadjacent segments, and optionally without any separation in thefunctional capabilities between adjacent segments. For example, anarticulated body having a two-segment ring frame skeleton 690′ system asshown in FIG. 23F may have a continuous axial series of inner and outerring frames 692, 694 that extends across the interface between thejoints such that the two segments can be bent in coordination with aconstant bend radius by directing similar inflation fluid quantities andpressures along the fluid supply channels associated with the twoseparate segments. As can be understood with reference to FIG. 23E,other than differing articulation states of the segments, there mayoptionally be few or no visible indications of where one segment endsand another begins.

Despite having many shared components (and a very simple and relativelycontinuous overall structure), functionally separating an elongateskeleton into segments provides tremendous flexibility and adaptabilityto the overall articulation system. Similar bend radii may optionally beprovided with differing stiffnesses by applying appropriately differingpressures to the opposed balloons 660, 662 of two (or more) segments 690i, 690 ii. Moreover, as can be understood with reference to FIG. 23D,two (or more) different desired bend radii, and/or two different lateralbend orientations and/or two different axial segments lengths can beprovided by applying differing inflation fluid supply pressures to theopposed contraction/extension balloon sets of the segments. Note thatthe work spaces of single-segment and two-segment systems may overlap sothat both types of systems may be able to place an end effector or toolat a desired position in 3D space (or even throughout a desired range oflocations), but multiple-segment systems will often be able to achieveadditional degrees of freedom, such as allowing the end effector or toolto be oriented in one or more rotational degrees of freedom in 6D space.As shown in FIG. 23H, articulated systems having more than two segmentsoffer still more flexibility, with this embodiment of ring frameskeleton 690′ having 4 functional segments 690 a, 690 b, 690 c, and 690d. Note that still further design alternatives may be used to increasefunctionality and cost/complexity of the system for a desired workspace,such as having segments of differing length (such as providing arelatively short distal segment 690 a supported by a longer segmenthaving the combined lengths of 690b, 690 c, and 690 d. While many of themulti-segment embodiments have been shown and described with referenceto to planar configurations of the segments where all the segments liein a single plane and are either straight or in a fully bentconfiguration, it should also be fully understood that the plurality ofsegments 690 i, 690 ii, etc., may bend along differing planes and withdiffering bend radii, differing axial elongation states, and/ordiffering stiffness states, as can be understood with reference to FIG.23G.

Catheters and other elongate flexible articulated structures having ringframe skeletons as described above with reference to FIGS. 20-23Hprovide tremendous advantages in flexibility and simplicity over knownarticulation systems, particularly for providing large numbers ofdegrees of freedom and when coupled with any of the fluid supply systemsdescribed herein. Suitable ring frames may be formed of polymers (suchas nylons, urethanes, PEBAX, PEEK, HDPE, UHDPE, or the like) or metals(such as aluminum, stainless steel, brass, silver, alloys, or the like),optionally using 3D printing, injection molding, laser welding, adhesivebonding, or the like. Articulation balloon substrate structures mayinitially be fabricated and the balloon arrays assembled with thesubstrates in a planar configuration as described above, with the arraysthen being assembled with and/or mounted on the skeletons, optionallywith the substrates being adhesively bonded to the radially innersurfaces of the inner rings and/or to the radially outer surfaces of theouter rings, and with helical or serpentine axial sections of thesubstrate bridging between ring frames. While extension and retractionballoons 660, 662 associated with the ring frame embodiments are shownas spherical herein, using circumferentially elongate (and optionallybent) balloons may increase an area of the balloon/skeleton interface,and thereby enhance axial contraction and extension forces. A hugevariety of modifications might also be made to the general ring-frameskeletal arrangement and the associated balloon arrays. For example,rather than circumferentially separating the balloons into three lateralorientations, alternative embodiments may have four lateral orientations(+X, −X, +Y, and −Y) so that four sets of contraction balloons aremounted to the frame in opposition to four sets of extension balloons.Regardless, while ring-frame skeletons have lots of capability andflexibility and are relatively geometrically simple so that theirfunctionality is relatively easy to understand, alternativeextension/contraction articulation systems having helical skeletonmembers (as described below) may be more easily fabricated and/or moreeasily assembled with articulation balloon array components,particularly when using the advantageous helical multi-lumen coresubstrates and continuous balloon tube structures described above.

First reviewing components of an exemplary helical framecontraction/expansion articulation system, FIGS. 24A-24E illustrateactuation balloon array components and their use in a helical balloonassembly. FIGS. 24F and 24G illustrate exemplary outer and inner helicalframe members. After reviewing these components, the structure and useof exemplary helical contraction/expansion articulation systems(sometimes referred to herein as helical push/pull systems) can beunderstood with reference to FIGS. 25 and 26.

Referring now to FIGS. 24A and 24B, an exemplary multi-lumen conduit orballoon assembly core shaft has a structure similar to that of the coredescribed above with reference to FIGS. 14 and 15. Core 702 has aproximal end 704 and a distal end 706 with a multi-lumen body 708extending therebetween. A plurality of lumens 710 a, 710 b, 710 c, . . .extend between the proximal and distal ends. The number of lumensincluded in a single core 702 may vary between 3 and 30, with exemplaryembodiments have 3, 7 (of which one is a central lumen), 10 (including 1central), 13 (including 1 central), 17 (one being central), or the like.The multi-lumen core will often be round but may alternatively have anelliptical or other elongate cross-section as described above. Whenround, core 702 may have a diameter 712 in a range from about 0.010″ toabout 1″, more typically being in a range from about 0.020″ to about0.250″, and ideally being in a range from about 0.025″ to about 0.100″for use in catheters. Each lumen will typically have a diameter 714 in arange from about 0.0005″ to about 0.05″, more preferably having adiameter in a range from about 0.001″ to about 0.020″, and ideallyhaving a diameter in a range from about 0.0015″ to about 0.010″. Thecore shafts will typically comprise extruded polymer such as a nylon,urethane, PEBAX, PEEK, PET, other polymers identified above, or thelike, and the extrusion will often provide a wall thickness surroundingeach lumen of more than about 0.0015″, often being about 0.003″ or more.The exemplary extruded core shown has an OD of about 0.0276″“, and 7lumens of about 0.004” each, with each lumen surrounded by at least0.004″ of the extruded nylon core material.

Referring still to FIGS. 24A and 24B, the lumens of core 702 may haveradial balloon/lumen ports 716 a, 716 b, 716 c, . . . , with each portcomprising one or more holes formed through the wall of core 702 andinto an associated lumen 710 a, 710 b, 710 c, . . . respectively. Theports are here shown as a group of 5 holes, but may be formed using 1 ormore holes, with the holes typically being round but optionally beingaxially elongate and/or shaped so as to reduce pressure drop of fluidflow therethrough. In other embodiments (and particularly those having aplurality of balloons supplied with inflation fluid by a single lumen),having a significant pressure drop between the lumen and the balloon mayhelp even the inflation state of balloons, so that a total cross sectionof each port may optionally be smaller than a cross-section of the lumen(and/or by limiting the ports to one or two round lumens). Typical portsmay be formed using 1 to 10 holes having diameters that are between 10%of a diameter of the associated lumen and 150% of the diameter of thelumen, often being from 25% to 100%, and in many cases having diametersof between 0.001″ and 0.050″. Where more than one hole is included in aport they will generally be grouped together within a span that isshorter than a length of the balloons, as each port will be containedwithin an associated balloon. Spacing between the ports will correspondto a spacing between balloons to facilitate sealing of each balloon fromthe axially adjacent balloons.

Regarding which lumens open to which ports, the ports along a distalportion of the core shaft will often be formed in sets, with each setbeing configured to provide fluid flow to and from an associated set ofballoons that will be distributed along the loops of the core (once thecore is bent to a helical configuration) for a particular articulatedsegment of the articulated flexible body. When the number of lumens inthe core is sufficient, there will often be separate sets of ports fordifferent segments of the articulated device. The ports of each set willoften form a periodic pattern along the axis of the multi-lumen core702, so that the ports provide fluid communication into M differentlumens (M being the number of different balloon orientations that are tobe distributed about the articulated device axis, often being 3 or 4,i.e., lumen 710 a, lumen 710 b, and lumen 710 c) and the patternrepeating N times (N often being the number of contraction balloonsalong each orientation of a segment). Hence, the multi-lumen coreconduit can function as a substrate that supports the balloons, and thatdefines the balloon array locations and associated fluid supply networksdescribed above. Separate multi-lumen cores 702 and associated balloonarrays may be provided for contraction and expansion balloons.

As one example, a port pattern might be desired that includes a 3×5contraction balloon array for a particular segment of a catheter. Thisset of ports might be suitable when the segment is to have three lateralballoon orientations (M=3) and 5 contraction balloons aligned along eachlateral orientation (N=5). In this example, the distal-most port 716 aof the set may be formed through the outer surface of the core into afirst lumen 710 a, the next proximal port 716 b to lumen 710 b, the nextport 716 c to lumen 710 c, so that the first 3 (M) balloons define an“a, b, c” pattern that will open into the three balloons that willeventually be on the distal-most helical loop of the set. The samepattern may be repeated 5 times (for example: a, b, c, a, b, c, a, b, c,a, b, c, a, b, c) for the 5 loops of the helical coil that will supportall 15 contraction balloons of a segment to the fluid supply system suchthat the 5 contraction balloons along each orientation of the segmentare in fluid communication with a common supply lumen. Where the segmentwill include expansion balloons mounted 1-to-1 in opposition to thecontraction balloons, a separate multi-lumen core and associated balloonmay have a similar port set; where the segment will include 2 expansionballoons mounted in opposition for each contraction balloon, twoseparate multi-lumen cores and may be provided, each having a similarport set.

If the same multi-lumen core supplies fluid to (and supports balloonsof) another independent segment, another set of ports may be providedaxially adjacent to the first pattern, with the ports of the second setbeing formed into an M′×N′ pattern that open into different lumens ofthe helical coil (for example, where M′=3 and N′=5: d, e, f, d, e, f, d,e, f, d, e, f, d, e, f), and so on for any additional segments. Notethat the number of circumferential balloon orientations (M) will oftenbe the same for different segments using a single core, but may bedifferent in some cases. When M differs between different segments ofthe same core, the spacing between ports (and associated balloonsmounted to the core) may also change. The number of axially alignedcontraction balloons may also be different for different segments of thesame helical core, but will often be the same. Note also that all theballoons (and associated fluid lumens) for a particular segment that areon a particular multi-lumen core will typically be either only extensionor only contraction balloons (as the extension and contraction balloonarrays are disposed in helical spaces that may be at least partiallyseparated by the preferred helical frame structures described below). Asingle, simple pattern of ports may be disposed near the proximal end ofcore shaft 702 to interface each lumen with an associated valve plate ofthe manifold, the ports here being sized to minimized pressure drop andthe port-port spacing corresponding to the valve plate thickness.Regardless, the exemplary core shown has distal ports formed usinggroups of 5 holes (each having a diameter of 0.006″, centerline spacingwithin the group being 0.012″), with the groups being separated axiallyby about 0.103″.

Referring now to FIGS. 24C and 24D, a continuous tube of flexibleballoon wall material 718 may be formed by periodically varying adiameter of tube wall material to form a series of balloon shapes 720separated by smaller profile sealing zones 722. Balloon tube 718 mayinclude between about 9 and about 290 regularly spaced balloon shapes720, with the sealing zones typically having an inner diameter that isabout equal to the outer diameters of the multi-lumen helical coreshafts 702 described above. In some embodiments, the inner diameters ofthe sealing zones may be significantly larger than the outer diametersof the associated cores when the balloon tube is formed, and thediameters of the sealing zones may be decreased (such as by heatshrinking or axially pull-forming) before or during assembly of theballoon tube and core shaft. The sealing zone may have a length ofbetween about 0.025″ and about 0.500″, often being between about 0.050″and about 0.250″. Decreasing the length of the sealing zone allows thelength of the balloon to be increased for a given catheter size so as toprovide larger balloon/frame engagement interfaces (and thus greaterarticulation forces), while longer sealing zones may facilitate assemblyand sealing between balloons so as to avoid cross-talk betweenarticulation channels.

Referring still to FIGS. 24C and 24D, the balloon shapes 720 of theballoon tube 718 may have diameters that are larger than the diametersof the sealing zones by between about 10% and about 200%, more typicallybeing larger by an amount in a range from about 20% to about 120%, andoften being from about 40% to about 75%. The thickness of balloon tube718 will often vary axially with the varying local diameter of the tube,the locally large diameter portions forming the balloon shapesoptionally being in a range from about 0.00008′ (or about 2 microns) toabout 0.005″, typically being from about 0.001″ and about 0.003″.Balloon tube 718 may initially be formed with a constant diameter andthickness, and the diameter may be locally expanded (by blow forming, byvacuum forming, by a combination of both blow forming and vacuumforming, or by otherwise processing the tube material along the balloonshapes 720), and/or the diameter of the balloon tube may be locallydecreased (by heat shrinking, by axial pull-forming, by a combination ofboth heat shrinking and pull forming, or by otherwise processing thetube material along the sealing zones), with the tube material oftenbeing processed so as to both locally expand the diameter along thedesired balloon shapes and to locally contract the diameter along thesealing zones. Particularly advantageous techniques for forming balloontubes may include the use of extruded polymer tubing corrugators,including the vertical small bore corrugators commercially availablefrom Unicore, Corma, Fraenkische, and others. Suitable custom molds forsuch pipe corrugators may be commercially available from GlobalMed,Custom Pipe, Fraenkische, and others. Still more advanced fabricationtechniques may allow blow or vacuum corrugation using a robotic shuttlecorrugator and custom molds, particularly when it is desirable to changea size or spacing of balloons along a continuous tube. It should benoted that while a single continuous balloon tube is shown, a pluralityof balloon tubes (each having a plurality (or in some cases, at leastone) balloon shape) can be sealingly mounted onto a single core.Regardless, the sealing zones will often have a material thickness thatis greater than that of the balloon shapes.

The balloon shapes 720 of the balloon tube 718 may each have arelatively simple cylindrical center section prior to assembly as shown.The tapers between the balloon center sections and the sealing zones cantake any of a variety of shapes. The tapers may, for example, be roughlyconical, rounded, or squared, and will preferably be relatively short soas to allow greater balloon/frame engagement for a given landing zonelength. More complex embodiments may also be provided, including formingthe balloon shapes with curved cylindrical center sections, optionallywhile corrugating or undulating the surfaces of the tapers so that theballoon tube overall remains relatively straight. The lengths of eachcenter section is typically sufficient to define an arc-angle of from 5to 180 degrees about the axis of the desired balloon assembly helix,more typically being from about 10 to about 50 degrees, the lengths ofthe center sections often being in a range from about 0.010″ to about0.400″ for medical applications, more typically being from about 0.020″to about 0.150″, and many times being in a range from about 0.025″ toabout 0.100″. The exemplary balloon shapes may have an outer diameter ofabout 0.051″ over a total balloon length (including the tapers) of about0.059″

As can be understood with reference to FIGS. 24C, 24D, 24E, and 24E-1,balloon tube 718 may be sealingly affixed to core 702, and thecore/balloon tube assembly may then be formed into a desired helicalshape. The balloon tube may be sealed over the helical core usingadhesive (such as any of those described above, often including UV-curedadhesives) thermal bonding, laser bonding, die bonding, and/or the like.Sealing of the balloons may also benefit from a compression structuredisposed over the balloon material to help maintain tube/core engagementwhen the balloons are inflated. Suitable compression structures ortechniques may include short sections of heat-shrink materials (such asPET) shrunk onto the sealing zones, high-strength filament windingswrapped circumferentially around the sealing zones and adhesivelybonded, swaging of metallic ring structures similar to marker bands overthe sealing zones, small bore crimp clamps over the sealing zones,heat-shrinking and/or pull forming the balloon tube onto the core, orthe like. Any two or more of these may also be combined, for example,with the balloon tube being adhesively bonded to the core tube byinjecting adhesive into the balloon tube around the sealing zone, heatshrinking the balloon tube and a surrounding PET sleeve over the sealingzone, and then swaging a metallic marker band over the sealing PETsleeve (so that the sleeve provides strain relief). Regardless, ports716 will preferably be disposed within corresponding balloon shapes 720and will remain open after the balloon/core assembly 730 is sealedtogether in the straight configuration shown in FIG. 24D. Shape settingof the balloon/core assembly from the straight configuration to thehelically curved configuration of FIG. 24E can be performed by wrappingthe assembly around and/or within a mandrel and heating the wrappedassembly. Helical channels may be included in the mandrel, which mayalso have discrete balloon receptacles or features to help ensurealignment of sets of balloons along the desired lateral balloon axes.Regardless, shape setting of the core/balloon assembly can help set theM different lateral orientations of the balloons, so that the balloonsof each set 720 i, 720 ii, 720 iii are aligned (as can be understoodwith reference to FIGS. 24E and 24E-1).

Referring now to FIGS. 24F and 24G, exemplary inner and outer helicalC-channel frames, 732 and 734 respectively, can be seen. Inner helicalframe 732 and outer helical frame 734 incorporate the modified C-channelframe 680 of FIG. 22a , but with the C-channels defined by axiallycontinuous helical walls 736 with flanges 740 along their proximal anddistal helical edges. The helical flanges are axially engaged by opposedballoons and allow inflation of the balloons to locally axially contractand/or extend the skeleton and catheter (or other articulatable body) ina manner that is analogous to the annular flanges of the ring framesdescribed above. An optional helical nub 742 protrudes axially into thechannel of inner ring frame 734 to allow the frames to pivot againsteach other along a flange/flange engagement, so that the nub couldinstead be included on the flange of the outer frame or on both (or maycomprise a separate structure that is axially sandwiched between theflanges of the two frames). Alternative embodiments may forego such apivotal structure altogether.

Referring now to FIGS. 25A-25D, a segment of an exemplary flexibleextension/contraction helical frame articulation structure 750(sometimes referred to herein as a push/pull helical structure)incorporates the components of FIGS. 24A-24G, and provides thefunctionality of the annular extension/contraction frame embodiments ofFIGS. 22B-221. Push/pull structure includes a skeleton defined by innerand outer helical frames 732, 734, and also includes three balloon/coreassemblies 730 a, 730 b, and 730 c, respectively. Each balloon/coreassembly includes a set of balloons at three lateral orientations, 720i, 720 ii, and 720 iii. Balloon/core assembly 730 b extends along ahelical space that is axially between a flange of the inner frame and aflange of the outer frame, and that is radially between a wall of theinner frame and a wall of the outer frame, so that the frames overlapalong this balloon/core assembly. Hence, when balloons 720 ofballoon/core assembly 730 inflate, they push the adjacent flanges apartand increase the overlap of the frames, inducing axial contraction ofthe skeleton, such that the balloons of this assembly function ascontraction balloons. In contrast, balloon/core assemblies 730 a and 730c are radially adjacent to only inner frame 732 (in the case of assembly730 a) or outer frame 734 (in the case of assembly 730 b). Expansion ofthe balloons 720 of assemblies 730 a, 730 c pushes axially againstframes so as to decrease the overlap of the frames, and acts inopposition to the inflation of balloons 720 of assembly 730 b. Hence,balloons 720 of assemblies 730 a, 730 c function as extension balloons.

Referring now to FIGS. 25A-25C, when all the contraction balloons 720 ofassembly 730 b are inflated and all the extension balloons of assemblies730 a, 730 c are deflated, the push/pull structure 750 is in a straightshort configuration as shown in FIG. 25A. Even partial inflation of theextension balloons and even partial deflation of the contractionballoons articulates push/pull structure 750 to a straight intermediatelength configuration, and full inflation of all extension balloons ofassemblies 730 a, 730 c (along with deflation of the contractionballoons) fully axially elongates the structure. As with the ringpush/pull frames, inflating contraction balloons 720 ii along onelateral orientation of assembly 730 b (with corresponding deflation ofthe extension balloons 720 ii of assemblies 730 a, 730 b) locallydecreases the axial length of the skeleton along that side, whileselective deflation of contraction balloons 720 i of assembly 730 b(with corresponding inflation of extension balloons 720 i of assemblies730 a and 730 c) locally increases the length of the skeleton, resultingin the fully laterally bent configuration of FIG. 25E. Note thatextension and contraction balloons along the 720 iii orientation may beinflated and deflated with the extension and contraction orientationballoons of orientation 720 ii so as to keep the curvature in the planeof the drawing as shown. Stiffness of the structure may be modulateduniformly or locally (with axial and/or orientation variations) asdescribed above regarding the ring frame embodiments. Similarly, thenumber of extension and contraction balloons along each orientation(which will often be associated with the number of loops of assemblies730 a, 730 b, etc) may be determined to provide the desired range ofmotion, resolution, and response. As described with reference to thepush/pull ring frame embodiments, the overall articulated portion of thestructure will often be separated into a plurality of independentlycontrollable segments.

Referring now to FIG. 25F, push/pull structure 750 will often include anouter flexible sheath 752 and an inner flexible sheath 754. Sheaths 752,754 may be sealed together at a distal seal 756 distal of the inflationlumens and balloons of assemblies 730, and one or more proximal seal(not shown) may be provided proximal of the balloons and/or near aproximal end of the catheter structure, so as to provide a sealed volumesurrounding the articulation balloons. A vacuum can be applied to thissealed volume, and can be monitored to verify that no leaks are presentin the balloons or inflation lumen system within a patient body.

Referring now to FIGS. 26A and 26B, an alternative push/pull structureomits one of the two extension balloon assemblies 730 a, 730 c, and usesa 1-to-1 extension/contraction balloon opposition arrangement asdescribed above with reference to FIGS. 23A and 23B. Note that thisembodiment retains balloon assembly 730 c that is radially adjacent toouter frame 734 (so that no balloons are visible even with the sheathremoved). Alternative embodiments may retain assembly 730 a and foregoassembly 730 c (so that balloons could be seen through a clear sheath,for example).

A variety of catheter sizes and capabilities may be provided, with thenumber of segments often being related to the size and lumens of thecores shaft. Core shaft 702 has an outer diameter of about 0.028″ and 7lumens, with 6 peripheral lumens having an inner diameter of about0.004″ readily available for formation of associated ports and use intransmitting inflation fluid to and from balloons. A central lumen mightbe used, for example, in monitoring of the vacuum system to verifyintegrity of the system. Core shaft 702 can be used, for example, in a14-15 Fr catheter system having two segments that are each capable ofproviding up to 120 degrees of bending (or alternatively more or lessdepending on the number of balloons ganged together on each channel),with such a system optionally capable of providing a bend radiussufficient to fit a 180 degree bend of the catheter within a space of 3inches or less, ideally within 2½ inches or less, and in some caseswithin 2 inches or less. Such a system may be beneficial for structuralheart therapies, for example, and particularly for mitral valvedelivery, positioning, and/or implantation. Other therapies may benefitfrom smaller catheter profiles, and do not need the bending forcesavailable from a 15 Fr catheter. Electrophysilogy therapies such as AFibablation from within an atrium of the heart may be good examples oftherapies which would benefit from the degrees of freedom that can beprovided in small structures using the systems described herein. Scalingthe 15 Fr system down for a 7-8 Fr ablation catheter might make use of adirectly scaled core having half the overall outer diameter and half thelumen inner diameter of core 702, as the pressure-containing stresses inthe material would scale with the lumen diameters. However, there may becost benefits to maintaining minimum lumen wall thicknesses that areabove 0.002″, preferably at or above 0.0025″, and ideally at or aboveabout 0.003″. Toward that end, and to provide 6 contraction or extensionlumens for two 3D push/pull segments along a common helical core alongwith a desirably small bend radius, it may be beneficial to use radiallyelongate core 764 having a 6 lumens that are all surrounded by at least0.003″ of material. Still further advantages may be provided by applyingthe smaller lumen and wall thickness dimensions of 7 Fr core to a 15 Frcatheter core size, as it results in a 12 inflation lumen core 766. Alarge 13^(th) lumen of this embodiment may help enhance flexibility ofthe segments, and can again be used to monitor system integrity using avacuum system. The 12 lumens may allow, for example, a continuouspush/pull structure to have 4 independently controllable 3D shape (4Dshape+stiffness) segments. A 16 inflation lumen core may be provided bycombining the smaller lumen and wall thickness with a radially elongatecross-section, allowing 5 independently controllable 3D segments. Itshould be understood that still further numbers of lumens at smallerprofiles are possible using known and relatively low cost multilumenextrusion techniques.

It should be understood that still further alternative embodiments maytake advantage of the beneficial components and assemblies describedherein. For example, as can be understood from the disclosure aboveregarding many of the flexible structures of FIGS. 3-12, inflation of aballoon may be resiliently opposed by a helical spring or other biasingstructure so that the spring deflates the balloon and urges a flexiblebody back toward a pre-balloon-inflation state when the inflation fluidis released from the balloon. Rather than relying on 6 dedicated opposedexpansion and contraction balloon channels for each segment (providingindependent contraction and expansion along each lateral orientation) inthe push/pull ring frame and push/pull helical frame embodimentsdescribed above, two or more of the channels (from the same segments orfrom different segments) may be grouped together to act as a commonbaising structure or fluid spring. As an example, all the contractionballoons along two adjacent segments might open to a single lumen thatis inflated to less than full pressure. Modulating pressure to thedifferent sets of extension balloons may still allow the extensionballoons to articulate each segment with three independent degrees offreedom, as the grouped contraction balloons could selectively beoverpowered by the extension balloons (like the coil springs) or may beallowed to deflate the extension balloons. In some embodiments, ratherthan relying on partial pressure of extension or contraction balloons,an elastomeric material may be mounted over the core of some or all ofthe extension or contraction balloons of a segment so as to passivelyoppose a set of the balloons.

Referring now to FIG. 27, an articulation controller 770 for directinginflation fluid to and from the actuation balloons of the systems willtypically have hardware and/or software configured and programmed togenerally seek to cause the articulable structure to assume a new actualposition or state X_(actual) in response to a commanded trajectory 772input by a system user. Many of the articulated flexible structuresdescribed herein may be included in robotic systems that can be analyzedand controlled using techniques associated with continuum robots, andthe articulated structures will often be under-constrained with morejoints then can be directly controlled by the system using standardcontroller. These excess or redundant degrees of freedom are oftenmanaged and made to cooperate using an internal compliance that directsthe joints to be at a similar angle relative to the next joint withinthe segment. These equal joint angles may help lead the system toward alowest potential energy state for the system. Other alternative goalsfor the excess joints of the system are described herein. The processorof the system will typically have software modules to determine the nextdesired position or state of the articulatable structure X_(iDesired),and will apply inverse catheter kinematics 774 to determine the nextdesired joint state Θ_(iDesired). A difference between an actual jointstate and the next desired joint state is determined to define a jointerror, and the desired joint state can be fedforward to a jointtrajectory planner 776 along with the joint error to define a jointerror trajectory. This joint trajectory can be used in an inversefluidic calculation 778 to determine command signals that can be fedinto a closed-loop valve controller 780 so as to provide an actuatedjoint state. In some embodiments, closed loop control of the valves maydepend on pressure sensing, and may be used to control to specificpressures as determined by valve inverse kinematics. The catheterdynamics and mechanics reaction to the actuated joint state (with theassociated environment interactions with the catheter such as tissueforces and the like) result in a new actual position or state X_(actual)of the articulated catheter system.

Feedback on the actual position or state of the articulated system tothe controller may be omitted in some embodiments, but other embodimentsmay benefit from such feedback to provide more precise movements andbetter correlation (from the system user's perspective) between thecommand inputs and the actual changes in state. Toward that end, thecontroller may optionally use one or more closed loop feedback pathways.In some embodiments, a feedback system that is partially or fullyexternal to the articulated structure 782 may sense the actual positionor state of the catheter or other articulated structure using alocalization sensor 784, such as an electromagnetic navigation system,an ultrasound navigation system, image processing coupled to 3D imaging(such as biplanor fluoroscopy, magnetic resonance imaging, computedtomography, ultrasonography, stereoscopic cameras, or the like; wherethe imaging modality may optionally also be used to produce imagespresented to the system user for image guided articulation). In manyembodiments, the feedback will be provided using signals obtained fromthe articulated system itself under an internal closed loop feedbacksystem 786. To obtain a measured shape or state of the articulatedstructure, a variety of known sensor technologies may be employed as anarticulated structure shape sensor 788, including optical fiber shapesensors (such as those using fiber Bragg gratings), electrical shapesensors (such as those which use elastically deformable circuitcomponents), or the like. The measured and/or sensed signals may beprocessed using inverse kinematics to derive associated measure and/orsensed joint states. Furthermore, balloon array pressure signals willoften be available from the pressure sensors of the system, along withinformation correlating the pressures with the joint or shape state ofthe articulated system. The history of inflation fluid directed to andexhausted from the articulation balloons may also be used to helpdetermine an estimated inflation fluid quantity present in each balloon(or set of balloons on a common inflation lumen). Where balloons aremounted in opposition or in parallel, the pressure and inflation fluidquantity of these related balloons on separate channels may also beavailable. Some or all of this pressure information may be processedusing a joint kinematics processor 790 to determine a pressure-derivedjoint position or state (including a derived position of thepressure-articulated joints making up the flexible structure kinematicchain Θ_(LDevived)). The pressure information, preferably along withinternal localization information and/or external localizationinformation, may also be used by the joint kinematic processor 790 toderive the loads on the joints, for determining of motion limits 775 asused by the joint trajectory planner 776, and the like. Where more thanone is available, the external localization-based feedback joint state,the internal shape-sensor based joint state, and the pressure-derivedjoint state may be rectified 792 and the rectified (or otherwise anyavailable) joint state compared to the desired joint state to determinethe joint error signal.

Referring now to FIG. 28, an exemplary data processing structure 800 forcontrolling the shape of a catheter or other articulated elongateflexible bodies described herein can be understood. Much of the dataprocessing occurs on a controller board 802 of reusable driver 804, withthe driver optionally comprising a hand-held capital equipment unit. Theinput device 806 may optionally include a separate workstation withwired or wireless data telemetry (so as to allow, for example, aninterventional cardiologist or the like to perform a portion of theprocedure while separated from the radiation field of a fluoroscopysystem), or input device 806 may be a user interface integrated into thehand-held driver, or both. Preferably, the valve manifold 808 willcomprise one of the modular plate manifold structures described herein,and will be contained within the hand-held driver unit 804. Canister 810may be affixed to the driver (directly or by coupling of the catheter tothe driver), and will often be included within a hand-held proximalassembly of deployment system that includes the driver, the proximalinterface of the catheter, and other proximal components of the catheter(such as the heart valve actuation or deployment device 813, or thelike) during use. Similarly, a battery of the system (not shown) may beintegrated into the driver 804, may be mounted to the proximal interfaceof the catheter, or both.

A catheter 812 or other elongate flexible body for use with driver 804will generally have a proximal interface 814 that mates with areceptacle 816 of the driver. As can be understood with reference to thedescriptions above, the mating of the proximal interface with thereceptacle will often provide sealed fluid communication between aballoon array of the catheter and the valves of the manifold assembly.Coupling of the proximal interface with the receptacle may also resultin coupling of electrical contacts of the driver 818 with electricalcontacts of the catheter 820, thereby facilitate access to internalshape sensor data, external localization data (which may employ apowered fiducial on the catheter and an external electromagnetic sensorsystem, or the like). Still further communications between the catheterand the driver may also be facilitated, including transmission ofcatheter identification data (which may include a catheter type forconfiguration of the controller, a unique catheter identifier so as tohelp inhibit undesirable and potentially deleterious re-use of thecatheter, and the like). As an alternative to (or in addition to)electrical communication of this data, catheter 812 may have an RFID,bar code, or other machine-readable tag on or near proximal interface814, and driver 804 may include a corresponding reader one or nearreceptacle 816.

Referring to FIGS. 27 and 28, the input device 806 and/or input sensorsassociated with processor board 802 may also be used to generateprocessor mode signals, for example, to switch between any of the systemmodes described herein. Input device 806 may, for example, include amode button or switch which allows the mode of the processor to beselected from among a group of modes such as a manual movement mode, anautomated movement mode, a follow-the-curve mode, an axial recoverymode, any of the other operational modes described herein (or any subsetthereof). In some embodiments, the processor mode may change in responseto sensor signals. For example, in response to a movement sensorindicating that a proximal housing containing the manifold or the likeis being manually moved with a movement above a threshold (such as amovement that is sufficient to be transmitted distally along thecatheter body into the patient), the processor may change from anautomated movement mode to a manual movement mode. This may allow, forexample, the system user to manually reposition the catheter withouthaving to wait to input a mode command. The system may, in response tomode change command or sensor signal associated with the beginning of amanual repositioning of the distal portion of the catheter, identify apre-move position of the distal portion of the catheter. The system canalso identify a post-move position of the distal portion, and can usethe difference between the pre- and post-move positions to update atransformation between the input and the output so as to maintaincoordination for the user. Optionally, sensed movements of the proximalhousing may be used during manual movement to derive articulationcommands, such as by sensing axial movement of the housing so as toestimate axial movement of the catheter body through the introducersheath (instead of or in addition to measuring relative motion betweenthe introducer and catheter) for calculating lateral deflection axialpropagation when in a follow-the curve mode.

Referring now to FIGS. 29A-30, an alternative proximal interface 830 ofthe catheter can be understood, along with how it can be mated to analternative receptacle 832 of an alternative modular manifold 834.Proximal interface 830 provides sealed communication between axiallyseparated ports of up to three multi-lumen shafts 836, with the ports ofthe multi-lumen shafts being sealed by axially compressing O-rings 838or other deformable sealing bodies interleaved between more rigidinterface members 840. Threaded compression members 842 maintain axialsealing compression between a proximal-most interface member and adistal-most interface member. Posts 844 of interface members 840 extendlaterally and parallel to each other. Each interface member 840 includesa post 844 for each multi-lumen shaft, and the number of interfacemembers included in proximal interface 830 is the same as the number ofindependently used lumens in each multi-lumen shaft, so that the postsform an array with the total number of posts being equal to the totalnumber of independent multi-lumen channels in the articulated structure.Lumens extend radially from the ports of the multi-lumen shaft, throughthe posts 844, and to an interface port surrounded by a cap ofdeformable seal material.

Referring to FIG. 30, receptacle 832 of manifold assembly 834 has aseries of indentations that correspond with posts 844 of proximalinterface 830. The indentations have surfaces that correspond to theposts and seal to the deformable caps with the interface ports each insealed fluid communication with an associated channel of an associatedplate module. In this embodiment, the receptacle surfaces of each platemodules is on a receptacle member 848. The receptacle members supportplate layers with channels formed between the layers, with MEMS valvesand pressure sensors mounted to the plates as described above. Here,however, the plates of adjacent plate modules may not be in directplate-plate contact, so that the supply and exhaust flows may extendaxially through the receptacle members, through the proximal interface,or through another structure of the manifold assembly.

Referring to FIGS. 30A and 30B, exemplary alternative proximal housings1002, 1004 are shown. Proximal housing 1002 here includes a manifoldhousing 1006 and an input housing 1008, with the input housingoptionally releasably mountable onto the manifold housing, typicallyusing quick disconnect mechanical couplers, electrical/mechanicalconnectors, magnetic and/or magnetically guided couplers, or the like.Alternative systems may have the input and manifold housings integratedor permanently affixed together, or separate structures (either or bothoptionally being separately mountable to a base station). Whendetachable, the manifold housing 1006 and input housing 1008 may eachcontain associated components of the processor system (such as one ormore manifold PCB board for the manifold housing, and one or more userinterface board for the input housing) and a battery or other powersource. The user interface processor components of input housing 1008can optionally be coupled with the processor components of the manifoldby wireless telemetry when separated; if/when the input is releasablymounted to the manifold, data and power may optionally be transmittedbetween the processor components included in the two different housingvia a detachable coupler that engages when the housings are matedtogether.

Referring to FIG. 30A, manifold housing 1006 is coupled to flexiblecatheter 1014 via a detachable catheter coupler or base, and adisposable pre-pressurized gas/liquid inflation fluid canister 1010 isalso detachably supported by the manifold housing. Manifold housing 1006has an associated manifold reference frame 1012 and is configured to beheld in space by a hand of the system user while the user inputsmovement commands using the hand holding the manifold and/or the otherhand. The user holding manifold housing 1006 may also manuallymanipulate the distal end of the catheter by axially moving the catheterthrough the insertion sheath and in/out of the patient body, optionally(at least in part) using the hand holding the manifold housing by movingthe manifold housing toward and away from the patient. The user may alsorotate the manifold about the axis of the catheter so as to manuallyrotate the distal end of the catheter. As keeping an axis of thecanister within a range of angles from upright may facilitate steadyflows of inflation fluid, a twist input 1016 may be mounted to manifoldhousing 1006 with the twist input configured to receive rotational inputabout a twist input axis 1018 that extends along the axis of thecatheter adjacent the manifold. In response to this twist input, theprocessor may be configured to articulate the catheter so that one,some, or all bends of the articulatable distal portion of the catheterprecess about the distal catheter axis, with the precess anglescorresponding to a twist angle input. This may allow the user tomanually use a combination of axial movements of the catheter with twistin a manner analogous to manipulation of an unarticulated guide catheteror the like with much better torsional correlation between the input andoutput, with less torsional whipping, and the like. As can be more fullyunderstood with reference to FIGS. 32A-35E and the associated text,gross movement of manifold housing 1006 in the hand of the user may besensed and used as an input for catheter articulation, with movementsensing optionally being provided by sensors supported by the manifoldhousing itself, by sensors supported by the input housing while theinput housing is mounted on the manifold housing, or by both.

Referring still to FIG. 30A, when separable housings are provided, whileselected components of the user interface (input, display, sound, etc.)may optionally be mounted to manifold housing 1006, movement commandinput components may be primarily or entirely supported by input housing1008. Input housing 1008 may include, for example, a joystick and/ortrackball for entry of movement commands in a plurality of degrees offreedom, with an exemplary input having an at least 3D joystick (andideally a 6D joystick) configured to receive movement commands in someor all of input roll, pitch, yaw, along with X, Y, and Z translation(all in an input reference frame 1018. Suitable 6D joysticks may becommercially available from 3Dconnexion (including the SpaceNavigator™3D motion controller) and other suppliers, and such 3D input devices maybe particularly well suited for providing movement commands as velocity(translation and/or rotation) input vectors. Gross movement of the inputhousing may be well suited for providing positional (translation and/orrotation) input vectors. Additional or alternative user interfacecomponents may include buttons associated with articulationorientations, toggle switches for adjusting input/output orientation(s),a touch screen, a clutch button, a processor mode button, a display, atouch screen, and/or the like. To help align input vectors with outputmotion vectors of the articulated catheter, the user may at leastroughly align input housing 1008 (and/or manifold housing 1006) with thegross anatomy of the patient, with the internal tissue of the patienttargeted for treatment (optionally as that tissue is shown in adisplay), or with a distal portion of the catheter (optionally as shownin a display). Toward that end, input housing 1008 may be elongate (tofacilitate axial alignment between the input and the elongatearticulated catheter distal portion) and have visual and/or tactilefeatures that differentiate the input proximal, distal, vertical, andlateral orientations (such as one or more axially offset user interfacecomponents and differentiated vertical thickness and lateral width).Some or all of the user interface components, the wireless telemetrycircuitry, the sensor structures, the processor components, the battery,and/or the like of input housing 1008 may be commercially available foror adapted from those of standard smart phones and other consumer mobilecomputing devices.

Referring to FIG. 30B, proximal housing 1004 includes an alternativemanifold housing 1006′ and will typically include a user interface1008′. User interface 1008′ may include user interface components of theinput housing 1008 described above, which may be integrated intomanifold housing 1006′, or may be supported by an input housingdetachably mountable on manifold housing 1006′ or kept separate.Manifold housing 1006′ has legs 1020 a, 1020 b, 1020 c, with the bottomsurfaces 1022 of the legs together defining a base surface that isstabile on a flat support surface 1024. The bottom surface of the legssupport the catheter above the support surface and orient the catheteradjacent the manifold so that the axis of the catheter angles distallydownward toward an introducer sheath. Support surface 1024 willtypically comprise the top of a small (less than 0.5 square meter),generally horizontal table that can be cantilevered over the patient,with the table either supported by lockable wheels or being mountable toa side-rail of the operating table. Advantageously, the user canmanually manipulate the catheter by grasping and moving the catheterbody distal of the manifold housing 1006′, and/or by grasping and movingmanifold housing 1006′. Axial manual movement of the catheter shaftthrough the introducer sheath can be accommodated by axial sliding ofbottom surfaces 1022 over the flat surface. Flexing of the catheter bodybetween the proximal housing and input sheath may accommodate any changein angle associated with the sliding movement, and/or the flat surfacemay optionally be tilted downward distally (toward the insertion sheathand the angle of the catheter body near the proximal housing, allowingmore even leg lengths) to decrease proximal bending of the catheter withaxial movement. Rotation of a twist input 1016 (see FIG. 30A) mounted tohousing 1006′ near the catheter can mimic manual rotation of thecatheter shaft, or the user can lift and manually rotate the manifoldhousing and catheter shaft. Still further alternative arrangements maybe provided, including stand systems that hold the manifold and allowrotation about the catheter axis, catheter/manifold couplers thataccommodate relative rotation, and the like. Regardless, the user canreadily alternate between manual advancement and other manipulation ofthe catheter within the patient body and automated manipulation of thedistal articulated portion of the catheter within the patient using thedrive system that is contained entirely within housing 1006′ and thecatheter mounted thereon. Optionally, the processor may switch betweenautomated and manual modes in response to movement sensors mounted tomanifold housing 1006′ (optionally by mounting of an input housingthereon). Related articulated catheter systems may have similar userinterface capabilities but quite different drive systems, includingcatheter systems having pull-wires actuated by electrical motors(optionally with no fluid manifold in the proximal housing) or bysyringe pumps pistons driven using fluid inflation/deflation valves anda gas/liquid canister similar to those described above. When separableinput and drive system housings are provided, once the catheter isgenerally in position the user may move input housing 1008′ to a desiredlocation so as to, for example, limit user orthopedic strain and/orexposure to radiation from fluoroscopic or other imaging systems.

Referring now to FIGS. 31A-31D, an alternative balloon-articulatedstructure 850 having a single multi-lumen core may be particularly wellsuited for smaller profile applications, such as for microcathetershaving sizes down to 2 or 3 Fr, guidewires, or the like. Articulatedstructure 850 generally has a proximal end 852 and a distal end 854 andmay define an axis therebetween. A frame 856 of the structure is shownby itself in FIG. 31C and is generally tubular, having a series of loops858 interconnected by axial struts 860. Two struts may be providedbetween each pair of adjacent loops, with those two struts beingcircumferentially offset by about 180 degrees; axially adjacent strutsbetween nearby loop pairs may be offset by about 90 degrees,facilitating lateral bending of the frame in orthogonal lateral bendingorientations. As will be understood from many of the prior framestructures described herein, apposed surface region pairs between loops858 will move closer together and/or farther apart with lateral bendingof frame 850, so that a balloon can be used to control the offsetsbetween these regions and thereby the bending state of the frame.

A multi-lumen core 862 is shown by itself in FIG. 31B, and extendsaxially within the lumen of frame 856 when used (as shown in FIG. 31D).Core 862 includes a plurality of peripheral lumens 864 surrounding acentral lumen 868. Central lumen 868 may be left open as a workingchannel of articulated structure 850, to allow the articulated structureto be advanced over a guidewire, for advancing a guidewire or toolthrough the articulated structure, or the like. An array 870 ofeccentric balloons 872 is distributed axially and circumferentiallyabout the multi-lumen core, with the array again taking the form of anM×N array, with M subsets of balloons being distributedcircumferentially, each of the M subsets being aligned along a lateralbending orientation (M here being 4, with alternative embodiments having1, 2, 3, or other numbers of circumferential subsets as describedabove). Each of the M subsets includes N balloons, with N typicallybeing from 1 to 20. The N balloons of each subset may be in fluidcommunication with an associated peripheral lumen 864 so that they canbe inflated as a group. Eccentric balloons 872 may optionally be formedby drilling ports between selected peripheral lumens 864 to the outersurface of the body of the core, and by affixing a tube of balloon wallmaterial affixed over the drilled body of multi-lumen core 862, with theinner surface of the balloon tube being sealingly affixed to an outersurface of the multi-lumen body of the core. Alternatively, eccentricballoons may be integral with the multi-lumen core structure, forexample, with the balloons being formed by locally heating anappropriate region of the multi-lumen core and pressurizing anunderlying lumen of the core to locally blow the material of themulti-lumen body of the core radially outwardly to form the balloons.Regardless, the balloons extend laterally from the body of themulti-lumen core, with the balloons optionally comprising compliantballoons, semi-compliant balloons, or non-compliant balloons. The shapeof the inflated balloons may be roughly spherical, hemispherical, kidneyshaped (curving circumferentially about the axis of the core),cylindrical (typically with a length:diameter aspect ratio of less than3:1, with the length extending radially or circumferentially), or somecombination of two or more of these.

When multi-lumen core 862 is assembled with frame 856 (as in FIGS. 31A,31C, and 31D), the body of the multi-lumen core is received in the lumenof the frame and balloons 872 are disposed between the apposed surfacesof loops 858. By selectively inflating one subset of balloons 872aligned along one of the lateral bending orientations, and byselectively deflating the opposed subset of balloons (offset from theinflated balloons by about 180 degrees), the axis of articulatablestructure 850 can be curved. Controlling inflation pressures of theopposed balloon subsets may vary both a curvature and a stiffness ofarticulatable structure 850, with increasing opposed inflation pressuresincreasing stiffness and decreasing opposed inflation pressuresdecreasing stiffness. Varying inflation of the laterally offset balloonsets (at 90 and 270 degrees about the axis, for example) may similarlyvariably curve the structure in the orthogonal bending orientation andcontrol stiffness in that direction. The profile of the single-coreassembly may be quite small, with an exemplary embodiment having anouter diameter of frame 856 at about 1.4 mm, an outer diameter of thebody of multi-lumen core 862 of about 0.82 mm, and an inner diameter ofthe peripheral lumens 864 of about 0.10 mm. The multi-lumen core bodyand balloons may comprise polymers, such as any of the extrusion orballoons materials described above, and the frame may comprise a polymeror metal structure, the frame optionally being formed by molding,cutting lateral incisions in a tube of material, 3D printing, or thelike. Note that the exemplary multi-lumen core structure includes 8peripheral lumens while the illustrated segment makes use of 4 lumens toarticulate the segment in two degrees of freedom; a second segment maybe axially coupled with the shown segment to provide additional degreesof freedom, and more lumens may be provided when still further segmentsare to be included.

Referring now to FIG. 32A, an articulation system 902 includes a housinginput device 904 and an articulated catheter 906 having 3 independentlyarticulatable segments 908 a, 908 b, 908 c. Each segment may have 3articulated degrees of freedom, including lateral bending in X and Yorientations, and axial elongation in a Z orientation. To controllateral bending of, for example, a distal segment 908 a, housing inputdevice 904 may, for example, have an X-Y joystick 910 that is configuredto be manipulated by a thumb 912 of a hand H that is holding the housinginput device. Ease of use of the input device may be enhanced byalignment between the X-Y joystick 910 and the X-Y articulation of thecatheter 906 that is induced by movement of the joystick. The preferredalignment is between the movement command as entered into the inputdevice and the resulting automated movement of segment 908 a, 908 b,and/or 908 c, per the perception of the surgeon, so that therelationship is comfortable or intuitive. The surgeon may primarilyperceive movement at the distal end of the catheter from an imageobtained by way of fluoroscopy (or some other remote imaging modality)and displayed to the surgeon on a screen or other display device. Thedesired alignment is typically not directly associated with a truealignment between the catheter tip and the input device, so that theactual orientation of the catheter tip and input device may be at anyrelative angle. The perception of orientation is related to the relativeorientation of the monitoring or imaging field (aka. monitor and cameraposition/angle) and to the display of the catheter tip image to thesurgeon. Suitable alignment may be achieved using a rotational alignmentinput 916 to electronically rotate the X-Y lateral articulation axes ofdistal segment 908 a, intermediate segment 908 b, and/or proximalsegment 908 c about the Z or elongate axis of the distal segment.Segments 908 a, 908 b and 908 c may be rotationally affixed togetherabout the Z axis, so that providing alignment with any may achievealignment with all three. Regardless, one or more additional joysticksor other input structures could be provided to provide control over theother degrees of freedom of articulated catheter 906. Alternatively,input for at least some articulation degrees of freedom may be providedby moving a housing 918 of housing input device 904 with hand H,significantly simplifying the user interface and allowing a single handof the user to provide intuitive input commands for 3, 4, 5, 6, 7, oreven 8 (for example, with the inclusion of X-Y joystick 910 or the like)or more articulated degrees of freedom of catheter 906, the articulateddegrees of freedom sometimes called the degrees of freedom in jointspace.

Referring now to FIG. 32B, and here addressing the rotational alignmentof joystick 910 using rotational alignment input 916, an image capturedevice 920 such as fluoroscopy system, MRI system, computer tomographysystem, ultrasound system, infrared or optical camera, or the like mayobtain an image of at least a distal portion of catheter 906. An image906′ of catheter 906 (including an image 908 a′ of distal segment 908 a)may be shown on a display 922, with the user generally directingmovement of the catheter with reference to the images of the catheterand adjacent tissue structures as shown in the display. As image capturedevice 920 may be at a different orientation than the user relative tothe catheter and tissue structures, and as the display may be at a stilldifferent orientation than both, absent alignment structures an inputcommand in a desired orientation (for example, in the Y− orientation)may result in a displayed articulation of distal segment 908 a in anarbitrary orientation (for example, in the X+ orientation).

A variety of components and approaches can be included to improveinput/output correlation. Catheter image 906′ will generally have anelongate shape and a visible distal end, and gross correlation betweeninput housing device 904 and the image of the catheter may optionally beprovided by an elongate shape of the housing input, and in some cases byhaving the user manually orient the housing so that the elongate shapeof the housing roughly corresponds with an orientation of the cathetershown in the display. Manually establishing alignment may be facilitatedby an elongate image of the distal portion of the catheter (so that anorientation of the axis of the catheter can be visually identified,optionally with reference to a recognizable distal catheter end), alongwith the elongate input housing shape (so that the axis of the inputhousing can be readily identified and manually rotated into alignmentwith the catheter axis in the image, optionally with reference to atactile differentiation between the proximal and distal ends of theinput). Such manual alignment may be analogous to the aligning of acomputer mouse with a display, and the alignment may be revised aftermanual or automated movements of the catheter. Alternative automatedalignment systems may make use of FBG or other catheter shape sensors,image capture and/or image processing software (such as that used in theEchoNavigator™ system commercially available from Phillips or others forfusing ultrasound and fluoroscopic image data), surgical navigationsystems (including the StealthStation™ system from Medtronic or othersystems having electromagnetic localization components), and the like.Regardless, rotational correlation between the articulations of distalsegment image 908 a′ and joystick 910 may optionally be provided,enhanced, or confirmed by making a series of small test articulationinput commands (for example in the Y− orientation) to the joystick whileholding housing 918 (see FIG. 32A) in a fixed orientation, observing thedisplayed orientation of distal segment 908 a′ articulation (forexample, initially in the X+ orientation), and providing inputcorrective input by actuating rotational alignment input 916 (forexample, resulting in incremental rotation of the lateral bending X-Yaxes about the Z axis of catheter 906 and/or distal segment 908 a (seeFIG. 32A).

Note that absolute correlation between the input and output orientationsneed not be provided or sought, as rough correlation may be sufficientto allow intuitive operation of the system 902. Note also that a varietyof alternative input and adjustment inputs or mechanisms may beprovided, including using trackballs, touchpads, joysticks, or a varietyof alternative X-Y articulation input devices; using thumbwheels,toggles, slides, or a variety of alternative rotational alignmentinputs; and/or using image recognition or relative position informationregarding the display and input housing to calculate transforms thatprovide the desired input/output rotational correlation. It should beunderstood that the X-Y articulation that may be electronically rotatedabout the Z axis of the catheter need not involve any actual rotation ofthe various articulation balloons or other articulation structures;typically, the mathematical transforms of the controller and/or valvedrivers will simply be revised so that alternative balloon subsets willbe inflated to generate lateral bending in differing orientations(though mechanical rotation may be used in some embodiments). It shouldalso be understood that the correlation between the lateral bendingorientations may, in some input control configurations, be altered byroll 926 of housing 918, while the correlations may not be altered withothers. For example, moving the whole control body or housing as a meansof control may help align command/visual axes. However, in someembodiments (including integrated manifold/input embodiments having apre-pressurized liquid/gas canister) it may be desirable to maintain theinput in an upright orientation. In such embodiments that also haverollers or a joystick mounted on the controller, repositioning of thecontroller housing may not coordinate or be intuitive with the cathetertip, and/or it may be awkward to reach or handle the inputs at theseother physical orientations.

Referring now to FIG. 33A, regardless of how the user interacts with thesystem to achieve lateral bending of distal segment 908 a, it will bebeneficial to include user interface components which help takeadvantage of the enhanced dexterity of the system that is available fromthe large numbers of degrees of freedom provided by flexible elongatearticulated structure 906. More specifically, distal segment may beconfigured to provide lateral bending in Xa and Ya orientations, alongwith axial elongation in a Za orientation, thereby allowing articulationin 3 degrees of freedom. Intermediate segment 908 b may similarly beconfigured for articulation in Xb, Yb, and Zb orientations, whileproximal segment 908 c may be configured for articulation in Xc, Yc, andZc orientations. Other segments may provide additional degrees offreedom. For 3 segment catheter 906, where each segment has 3 degrees offreedom, a joystick (or other X-Y input) that receives movement commandsfor lateral bending of the distal segment may be helpful, but the systemmay benefit from additional input mechanisms. Table 2 is a partialtop-level mapping of input and articulation degrees of freedom of inputhousing system 902, which may be helpful for identifying additionalinput structures and techniques.

TABLE 2 INPUT OUTPUT Joystick Xjoystick Xa Segment A Yjoystick YaHousing Za Xb Segment B Yb Zb Xc Segment C Yc Zc

While rotational alignment input 916 does provide an input for assistingalignment of the input command movements and displayed articulations,once alignment is established that input may not be used during activearticulation. Fortunately, alignment of the orientation about the Z axisof the distal segment should also result in rotational alignment aboutthe Z axes of the other segments (as all of the segments arerotationally coupled together, and can be substantially rotationallyaligned), so that a single rotational alignment procedure may besufficient. Regardless, as suggested by Table 2, it may be beneficialfor movement of housing 918 of housing input device 904 to be used as aninput for entering movement commands so as to generate articulation ofcatheter 906. It should be noted that there may (or may not) be moredegrees of freedom in the articulated segments of the catheter thanthere are inputs from the user. Mechanical constraints from the tissuealong the catheter may make use of some or all of these potentiallyexcess degrees of freedom. Alternatively, the processor may use theavailable degrees of freedom to further one or more goal that improvessystem performance (such as minimizing drive fluid use, driving thesystem toward a state having desirable stiffness characteristics,minimizing non-anchoring tissue engagement forces, or the like).Suitable control arrangements for using the flexibility of kinematicsystems having more than the minimum required degrees of freedom for atask often analyze the available alternatives that might fulfil aprimary movement command as a null-space, and suitable controllers fortaking advantage of the large numbers of the degrees of freedom that maybe provided by the catheters described herein can be determined frompublic null-space control literature.

There are a wide variety of correlations that might be used to completethe mapping of Table 2, some of which are reviewed below. In general,however, housing 918 can be moved in H (an integer from 1 to 6) degreesof freedom to define input commands, and those H input degrees offreedom can be used to provide input movement commands for at least Harticulation degrees of freedom of catheter 906. For example, where theinput command sensor system generates signals responsive to movement ofhousing H in 6 degrees of freedom, those 6 housing degrees of freedommay be used to calculate command movements for at least 6 articulationdegrees of freedom. Additional input structures can be included on thehousing or other input devices for articulation degrees of freedom thatare not associated with movement of the housing (including joystick 910or further additional input devices), or the controller may determinecommands to take advantage of what might otherwise be excess orredundant degrees of freedom of the articulated structure. As a coupleof simple examples, the processor may distribute axial elongation evenlyamong the segments, or may seek to maintain one or two of the segmentsin a nominal or mid-length configuration (in which lateral and/orvertical bending may be most nearly planar), or may maintain a positionalong the catheter with limited lateral displacement (such as to passthrough the septal wall or the like).

Referring now to FIGS. 33B and 33C to review the six potential inputdegrees of freedom of housing 918, the orientational degrees of freedominclude pitch 924 (here rotation about the X axis of housing inputdevice 904), roll 926 (rotation about the Z axis), and yaw 928 (rotationabout the Y or vertical axis). Translational degrees of freedom includeaxial translation along the Z axis 930, up or down translation along theY axis 932, and lateral translation along the X axis 934.

Referring now to FIG. 34, a number of alternative sensor structures andsystems may be used to generate signals indicative of movement ofhousing 918. As can be understood from the description above, a proximalportion of catheter 906 extending between housing 918 and an introducersheath 936 (or the access site into the patient) may have a shape sensorsuch as a fiber Bragg grating (FBG), flexible electrical componentsprinted on the structures of the catheter, or the like. Electromagneticnavigation structures may be included in the housing, or the housing mayhave markers (such as high-contrast spheres, printed QR codes,identifiable symbols, or the like) to facilitate optical localization ofthe housing using commercially available stereoscopic navigationsystems. In some embodiments, most or all of the active components ofthe housing movement sensor system may be contained in the housing, forexample, by including the FBG optical and processing components in thehousing. As another example, rather than relying on externalstereoscopic imaging for housing locations images, an image capturedevice 938 (such as a high definition camera, and infrared camera, astereoscopic camera, or the like) may be mounted to housing 918, withthe processor in the housing performing image processing to derivehousing movement data. Suitable image capture devices may include theRealSense 3D camera system available from Intel, the Structure IO systemavailable from Occipital, Inc., and the like. One or more referencemarker 940 may be mounted at a fixed location to facilitate calculationof movement data using techniques similar to those developed anddescribed for indoor navigation using cell phone image data. Othertechnologies developed for cell phones may be employed as a housingmovement sensor, including MEMS accelerometers, MEMS gyroscopes, MEMSinertial navigation units (INU's), and the like. As some clinicalsettings for use of catheter 106 may have electromagnetic noise thatcould interfere with a magnetometer of an INU, it may be beneficial toadjust for drift of accelerometers and/or gyroscopes using data from ashape sensing FBG, an image sensor, or the like. Suitable signalprocessing for use in calculating a pose and/or movement of housingusing data from MEMS sensors and image data may be found, for example,in one or more of the following references:

-   http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4695469/-   https://www.researchgate.net/publication/261267019_Indoor_navigation_system_using_image_a    nd_sensor data_processing_on_a_smartphone-   http://www.doc.ic.ac.uk/teaching/distinguished-projects/2013/a.chandgadkar.pdf-   http://www.google.com/patents/WO2014128507A2?cl=en-   https://www.researchgate.net/publication/261551014    An_inertial_and_QR_code_landmarks-based_navigation_system_for_impaired_wheelchair_users

A range of alternative motion sensing systems that have been welldescribed in numerous references may be used, with many of thetechnologies being commercially available or readily assembled from opensource components. Visual Odomotry (VO), Simultaneous Localization andMapping (SLAM, including visual-inertial variants), fiducial andmarkerless camera pose tracking, inertial and optical data fusion, andthe like have been well developed for augmented reality and otherapplications, and suitable analytical tools may be commerciallyavailable from Vicon, Kudan, and others, or obtained from the ARToolKitopen source library or other sources, with many of these tools beingsuitable for use with sensors that are configured to be included in amobile device such as a smartphone, tablet, or the like. Regardless,combining of data from a 1, 2, or 3 D accelerometer, a 1, 2, or 3 Dgyroscope, a shape sensor coupled to catheter 906, and/or image capturedevice 938 can sense movement of housing 918 so as to receive 2, 3, 4,5, or 6 movement command input degrees of freedom. The input degrees offreedom may include any one or more of the three orientational degreesof freedom, or any one or more of the three translational degrees offreedom, or both.

Referring now to FIGS. 35A, 35B, and TABLE 3, one simplified exemplarymapping of the input degrees of freedom of housing input device 904 tothe articulated degrees of freedom of the three segment 908 of catheter906 helps to illustrate how sensed movement of the housing can be usedto help the user exercise control over a large number of articulationdegrees of freedom, without having to include a large number of separateinput devices or the like. For example, as shown in FIG. 35A, pitch 924of housing 918 may optionally be coupled to vertical bending Yb ofintermediate segment 108 b, while yaw 928 of housing 918 may optionallybe coupled to lateral bending Xb of the intermediate segment. Lateraltranslation 934 of housing 918 may be coupled to lateral bending Xc ofproximal segment 108 c, while vertical translation 932 of housing 918may be coupled to vertical bending Yc of proximal segment 108 c. Axialtranslation 930 of housing 918 may be coupled to axial elongation ofany, some, or all of the segments Za, Zb, and/or Zc. While suchrelatively simplistic input/output mapping may be used in someembodiments, more sophisticated relationships between the user's commandmovements of the housing and the corresponding automated movements ofthe articulated catheter may help avoid confusion and improveease-of-use.

TABLE 3 INPUT OUTPUT Joystick Xjoy stick Xa Segment A Yjoy stick YaHousing Axial Translation Za Yaw Xb Segment B Pitch Yb Axial TranslationZb Lateral Translation Xc Segment C Vertical Translation Yc AxialTranslation Zc

The mapping of the input degrees of freedom of housing 918 to thearticulation degrees of freedom of catheter 906 couplings may, forexample, be configured so as to at least roughly mimic movements near adesired location relative to the housing (such as coupling center 942below joystick 910) in the induced movements of catheter 906 at adesired coupling center 940 of the catheter as if, for example, the handof the user where grasping the catheter at or adjacent coupling center940 (the coupling center optionally being adjacent where distal segment908 a is mounted to intermediate segment 908 b). Even in the simplemapping of FIGS. 35A and 35B, lateral and vertical articulations of theintermediate segment, being immediately proximal of that location, willbe largely coupled with the orientation of the shaft at couplinglocation 940 (though there will also be some translation), while lateraland vertical articulation of the proximal segment may be more coupledwith translation at the coupling location as schematically illustratedin FIG. 35C (though there will also be some rotation). Other couplingsmay be somewhat more complex: Axial elongation of intermediate andproximal segments 908 b, 908 c may both be coupled with axialdisplacement of coupling location 940; axial elongation of distalsegment 908 a will not, but artificially coupling elongation of at leastthe distal and intermediate elongations Za, Zb with axial translation ofthe housing may extend the range of correlated axial translation and maynot induce too much confusion. More generally, the system may takeadvantage of the excess articulation degrees of freedom provided by 3 ormore segments with three degrees of freedom each to advance any of awide variety of goals, including minimizing use of balloon inflationfluid, maintaining the segments near the centers of their ranges ofmotion and/or straight, inhibiting collisions of the catheter withitself, minimizing tissue engagement forces, and the like. Note thatroll 926 of housing 918 may optionally alter the correlation betweenlateral and vertical bending (similar to varying the rotationalalignment input 916) so as to maintain the appearance of grasping androtating the segment about coupled location 940, relying on modificationof the lateral and vertical transforms of the distal, intermediate, andoptionally the proximal segment rather than directly coupling of aninput degree of freedom of housing 918 to an associated articulationdegree of freedom of catheter 906. Still further alternative goals maybe achieved, for example, where first and second segments have helicalstructures that are wound in opposed directions, at a given location forthe distal end of the catheter a roll orientation of the distal endabout the Z axis can be controlled by adjusting a length of the firstsegment and compensating by appropriate adjustment of the secondsegment.

Referring now to FIG. 35D, a more sophisticated mapping of the movementof housing 918 will more likely take advantage of the controlarchitecture to more effectively map input command movements of housing918 to displayed movements of catheter 906, with movements of thehousing in a single input degree of freedom often inducing combinedmovements of articulation degrees of freedom at a desired couplinglocation 940′, so that the articulated catheter appears to move withoutput movements that correspond to those of the housing. For example,yaw 928 of housing 918 about input center 942 may result in acombination of elongation and lateral deflections of both theintermediate and proximal segment so as to more precisely mimic yaw atcoupling location 940 than could be generated by articulation within anysingle segment. The desired combination of deflections may be calculatedusing an appropriate transformation for the forward and inversekinematics, and by solving the vector units between the input andoutput. Similar mappings of pitch and yaw movements of the housing aboutinput center 942 to pitch and yaw of the catheter about couplinglocation 940, and of the three translation degrees of freedom totranslation degrees of freedom of the coupling location are shown inTABLE 4. These aligned mappings may help the user to maintain accuratecontrol over the catheter by providing output movements that the userperceives as corresponding intuitively with input command movements.

TABLE 4 INPUT OUTPUT Joystick Xjoystick Xa Segment A Yjoystick YaHousing Axial Translation Axial Translation Segments A, (motions Yaw YawB, and C sensed at Pitch Pitch (motions coupling Lateral TranslationLateral Translation calculated at location of Vertical Vertical couplinghousing) Translation Translation location of catheter)

In many embodiments, movement of housing 918 will only induce movementof catheter 906 while a clutch input 944 is being squeezed by the hand;releasing of the clutch may halt movement of catheter 906. Optionally,the input/output correlation between the housing and the catheter mayprovide a velocity controller so that movement of housing 918 whileclutch input 944 is depressed may provide a velocity command, initiatingmovement of catheter 906 in the orientation of the housing movement andwith a velocity proportional to the scale of the housing movement.Alternatively, an input/output correlation between the housing and thecatheter may provide a position controller so that movement of housing918 while clutch input 944 is depressed may provide a position command,initiating movement of catheter 906 in the orientation of the housingmovement and for a distance proportional to the scale of the housingmovement. In many embodiments, the coupling center on the catheter maybe adjacent the proximal or distal end of the deliverable therapeutic ordiagnostic tool, such as a prosthetic valve. This might be at a distaltip of the distal segment, and may make the user feel like they areholding a pair of pliers with something in the pliers, that somethingbeing the tool (such as the prosthetic valve).

Referring now to FIG. 35E, an alternative housing input device 960includes a first housing portion 962 that can optionally be releasablyattached to a second housing portion 964 (with alternative systemsemploying input devices and manifold housings that remain separate).Together, the first and second housing portions include some or all ofthe functional components described above regarding housing input device902 of FIGS. 32A, 32B, 33B, 33C, 34, and 35A-35D. For example, firsthousing portion 962 will generally include articulation user interfacecomponents such as the housing motion sensing system (for providingmovement commands to the processor), while second housing portion 964will generally include the fluid supply canister, manifold, andreceptacle for receiving the connector of the catheter. Both firsthousing portion 962 and second housing portion 964 may include a powersource (such as a battery) and circuitry for wireless transmission ofdata between the user interface components and the valve manifold. Thesystem processor may be included in first housing portion 962 or insecond housing portion 964, but will often be distributed between thetwo, with at least some command signal processing being performed in thefirst housing portion and at least some valve signal processing beingperformed in the second housing portion. Optionally, correspondingelectrical contacts of the portions engage when they are latchedtogether to more efficiently transmit data and/or to share power, andalternative housing input device can be used as a single unit asdescribed above. Alternatively, the user may detach first housingportion 962 from second housing portion 964, and may use the firsthousing portion to input movement commands to the catheter system byactuating the clutch and moving the first housing portion with atranslational movement 930, 932, 934 and/or a rotational movement 924,926 928 without having to manipulate the additional weight and volume ofthe second housing portion. The system user may optionally take and usefirst housing portion 962 at a distance (such as 1-10 meters) away fromthe patient, so as to decrease exposure of the system user toirradiation associated with fluoroscopy or the like. Alternatively, asecond user interface housing portion or workstation may be providedwith a radiation barrier disposed between the user and the patient. Instill further alternative embodiments, two separate (rather thanconnectable) housings may be provided, and/or a flexible signalconduction cable or tether may couple the user input and manifoldhousings together (rather than relying on wireless telemetry).

Referring now to FIGS. 36-36D, an alternative articulated cathetersystem has a flexible joystick input 950 system with a reverse drivesystem 952 and clutches 954, 956 so that the joystick can be axiallydecoupled from a catheter body 958, axially coupled to the catheter body(so that, for example, the catheter body moves in the same axialdirection as the joystick when the user moves the joystick distally), orreverse coupled to the catheter body (so that, for example, the catheterbody moves distally when the joystick is withdrawn proximally).

While the exemplary embodiments have been described in some detail forclarity of understanding and by way of example, a variety ofmodifications, changes, and adaptations of the structures and methodsdescribed herein will be obvious to those of skill in the art. Hence,the scope of the present invention is limited solely by the claimsattached hereto.

1. (canceled)
 2. A method for moving a body using a hand of a user, animage of the body being shown on a display, the method comprising:providing a housing configured to be supported with the hand, thehousing containing an input sensor system including an image capturedevice; measuring, using the image capture device of the input sensorsystem, a movement of the housing induced by the hand in four degrees offreedom so that the housing translates along first and second positionalinput axes and rotates around first and second orientational input axes;determining a movement of the body in response to the movement of thehousing so that the image of the body as shown in the display translatesalong first and second display translation axes aligned along the firstand second input axes, respectively; determining a rotation of the bodyin response to the rotating of the housing so that the image of the bodyas shown in the display rotates on the screen about first and seconddisplay rotation axes aligned along the first and second input rotationaxes, respectively; and inducing the determined movement of the body andthe determined rotation of the body so that the distal portion of thebody appears to the user to move in correlation with the movement of thehousing in the hand of the user.
 3. The method of claim 2, wherein thebody comprises an elongate articulated body having a proximal end and adistal portion, the distal portion being disposed in a patient bodyduring the movement and the rotation of the body, the movement androtation of the body being performed by articulating the articulatedbody within the patient body.
 4. The method of claim 3, wherein thearticulated body comprises an articulated catheter body, wherein thearticulating of the catheter body is performed by directing fluidpressure to a plurality of actuators.
 5. The method of claim 4, whereinthe actuators comprise an array of balloons disposed along the catheterbody, and wherein articulating of the catheter body is performed byselectively inflating subsets of the array of balloons offsetcircumferentially and axially along the catheter body.
 6. The method ofclaim 4, wherein the fluid induces independent bending of first andsecond articulating segments of the catheter body, the first segmentbeing proximal of the second segment, the distal portion being distal ofthe second segment, wherein the distal portion moves in the patient bodywith translation and rotation corresponding to the movement of thehousing.
 7. The method of claim 3, wherein the distal portion of theelongate body is disposed in an atrium of a heart, and wherein themovement of the elongate body is performed so as to align a structuralheart tool disposed near the distal portion of the elongate body with avalve tissue of the heart.
 8. The method of claim 3, further comprisingsensing a shape of the articulated body or location of the distalportion of the elongate body with an articulation feedback sensor, anddriving the articulating of the elongate body in response to the inputsensor and the feedback sensor so that movement and rotation of thedistal portion corresponds with the movement and rotation of thehousing.
 9. The method of claim 8, wherein the feedback sensor comprisesa localization sensor and further comprising sensing a location of thedistal portion in the patient body.
 10. The method of claim 9, whereinthe feedback sensor comprises an electro-magnetic position sensor. 11.The method of claim 8, wherein the feedback sensor comprises a shapesensor and further comprising sensing a shape of the articulated bodywith the feedback sensor.
 12. The method of claim 11, wherein the shapesensor comprises a fiber optic shape sensor.
 13. The method of claim 2,wherein the input sensor system comprises an at least 2D accelerometerand/or an at least 2D gyroscope, and further comprising correcting asensed movement of the housing using image data from the image capturedevice so as to inhibit drift in the sensed movement.
 14. A method forinducing movement of an image of a distal portion of an elongatearticulated body using a hand of a user, the image of the distal portionbeing shown on a display, the image of the distal portion being adjacenta tissue image in the display, the method comprising: providing ahousing configured to be supported with the hand, the housing containingan input sensor system, a battery, and a wireless signal transmitter;measuring, using input sensor system, a movement of the housing inducedby the hand in four degrees of freedom so that the housing translatesalong first and second positional input axes and rotates around firstand second orientational input axes; transmitting, with the wirelesssignal transmitter, command signals in response to the measured movementof the housing; determining a movement of the distal portion in responseto the movement command so that the image of the distal portion as shownin the display translates along first and second display translationaxes aligned along the first and second input axes, respectively;determining a rotation of the distal portion in response to the rotatingof the housing so that the image of the distal portion as shown in thedisplay rotates on the screen about first and second display rotationaxes aligned along the first and second input rotation axes,respectively; and inducing the determined movement of the image of thedistal portion of the articulated body and the determined rotation ofthe image of the articulated body by articulating the articulated bodyso that the distal portion of the articulated body appears to the userto move in correlation with the movement of the housing in the hand ofthe user.